Many changes

A large proportion of these changes relate to changing the way
packages relate to derivations. Previously, a package at a given
revision had a single derivation. This was OK, but didn't account for
multiple architectures.

Therefore, these changes mean that a package has multiple derivations,
depending on the system of the derivation, and the target system.

There are multiple changes, small and large to the web interface as
well. More pages link to each other, and the visual display has been
improved somewhat.

10 files changed, 981 insertions, 309 deletions

diff --git a/guix-data-service/comparison.scm b/guix-data-service/comparison.scm
index e3190ad..8688f84 100644
--- a/guix-data-service/comparison.scm
+++ b/guix-data-service/comparison.scm
@@ -12,20 +12,56 @@
             package-data-vhashes->new-packages
             package-data-vhashes->removed-packages
             package-data-version-changes
-            package-data-other-changes))
+            package-data-derivation-changes))
 
 (define (package-differences-data conn base_guix_revision_id target_guix_revision_id)
   (define query
-    "WITH base_packages AS (
-  SELECT packages.* FROM packages INNER JOIN guix_revision_packages ON packages.id = guix_revision_packages.package_id WHERE revision_id = $1
+    "
+WITH base_packages AS (
+  SELECT packages.*, derivations.file_name,
+    package_derivations.system, package_derivations.target
+  FROM packages
+  INNER JOIN package_derivations
+    ON packages.id = package_derivations.package_id
+  INNER JOIN derivations
+    ON package_derivations.derivation_id = derivations.id
+  WHERE package_derivations.id IN (
+    SELECT guix_revision_package_derivations.package_derivation_id
+    FROM guix_revision_package_derivations
+    WHERE revision_id = $1
+  )
 ), target_packages AS (
-  SELECT packages.* FROM packages INNER JOIN guix_revision_packages ON packages.id = guix_revision_packages.package_id WHERE revision_id = $2
+  SELECT packages.*, derivations.file_name,
+    package_derivations.system, package_derivations.target
+  FROM packages
+  INNER JOIN package_derivations
+    ON packages.id = package_derivations.package_id
+  INNER JOIN derivations
+    ON package_derivations.derivation_id = derivations.id
+  WHERE package_derivations.id IN (
+    SELECT guix_revision_package_derivations.package_derivation_id
+    FROM guix_revision_package_derivations
+    WHERE revision_id = $2
+  )
 )
-SELECT base_packages.name, base_packages.version, base_packages.package_metadata_id, base_packages.derivation_id, target_packages.name, target_packages.version, target_packages.package_metadata_id, target_packages.derivation_id
+SELECT base_packages.name, base_packages.version,
+  base_packages.package_metadata_id, base_packages.file_name,
+  base_packages.system, base_packages.target,
+  target_packages.name, target_packages.version,
+  target_packages.package_metadata_id, target_packages.file_name,
+  target_packages.system, target_packages.target
 FROM base_packages
-FULL OUTER JOIN target_packages ON base_packages.name = target_packages.name AND base_packages.version = target_packages.version
-WHERE (base_packages.id IS NULL OR target_packages.id IS NULL OR base_packages.id != target_packages.id)
-ORDER BY base_packages.name, base_packages.version, target_packages.name, target_packages.version")
+FULL OUTER JOIN target_packages
+  ON base_packages.name = target_packages.name
+  AND base_packages.version = target_packages.version
+  AND base_packages.system = target_packages.system
+  AND base_packages.target = target_packages.target
+WHERE
+  base_packages.id IS NULL OR
+  target_packages.id IS NULL OR
+  base_packages.id != target_packages.id OR
+  base_packages.file_name != target_packages.file_name
+ORDER BY base_packages.name DESC, base_packages.version, target_packages.name, target_packages.version")
 
   (exec-query conn query (list base_guix_revision_id target_guix_revision_id)))
 
@@ -40,7 +76,7 @@ ORDER BY base_packages.name, base_packages.version, target_packages.name, target
 
   (apply values
          (fold (lambda (row result)
-                 (let-values (((base-row-part target-row-part) (split-at row 4)))
+                 (let-values (((base-row-part target-row-part) (split-at row 6)))
                    (match result
                      ((base-package-data target-package-data)
                       (list (add-data-to-vhash base-row-part base-package-data)
@@ -63,24 +99,29 @@ ORDER BY base_packages.name, base_packages.version, target_packages.name, target
     derivation-data))
 
 (define (package-data-vhash->derivations-and-build-status conn packages-vhash)
-  (define (vhash->derivation-ids vhash)
+  (define (vhash->derivation-file-names vhash)
     (vhash-fold (lambda (key value result)
                   (cons (third value)
                         result))
                 '()
                 vhash))
 
-  (let* ((derivation-ids
-          (vhash->derivation-ids packages-vhash))
+  (let* ((derivation-file-names
+          (vhash->derivation-file-names packages-vhash))
          (derivation-data
-          (select-derivations-and-build-status-by-id conn derivation-ids)))
+          (select-derivations-and-build-status-by-file-name
+           conn
+           derivation-file-names)))
     derivation-data))
 
 (define (package-data-vhash->package-name-and-version-vhash vhash)
   (vhash-fold (lambda (name details result)
-                (vhash-cons (cons name (first details))
-                            (cdr details)
-                            result))
+                (let ((key (cons name (first details))))
+                  (vhash-cons key
+                              (cons (cdr details)
+                                    (or (and=> (vhash-assoc key result) cdr)
+                                        '()))
+                              (vhash-delete key result))))
               vlist-null
               vhash))
 
@@ -99,16 +140,29 @@ ORDER BY base_packages.name, base_packages.version, target_packages.name, target
                  base-packages-vhash)))
 
 (define (package-data-vhash->package-versions-vhash package-data-vhash)
+  (define (system-and-target<? a b)
+    (if (string=? (car a) (car b))
+        (string<? (cdr a) (cdr b))
+        (string<? (car a) (car b))))
+
+  (define (add-version-system-and-target-to-alist alist data)
+    (match data
+      ((version package-metadata-id derivation-id system target)
+       (let ((systems-for-version (or (and=> (assoc version alist) cdr)
+                                      '())))
+         `((,version . ,(sort (cons (cons system target)
+                                    systems-for-version)
+                              system-and-target<?))
+           ,@(alist-delete version alist))))))
+
   (vhash-fold (lambda (name details result)
                 (let ((version (first details))
-                      (known-versions (vhash-assoc name result)))
-                  (if known-versions
-                      (vhash-cons name
-                                  (cons version known-versions)
-                                  (vhash-delete name result))
-                      (vhash-cons name
-                                  (list version)
-                                  result))))
+                      (known-versions (or (and=> (vhash-assoc name result) cdr)
+                                          '())))
+                  (vhash-cons name
+                              (add-version-system-and-target-to-alist known-versions
+                                                                      details)
+                              (vhash-delete name result))))
               vlist-null
               package-data-vhash))
 
@@ -124,30 +178,42 @@ ORDER BY base_packages.name, base_packages.version, target_packages.name, target
                         (begin
                           (if (equal? base-versions target-versions)
                               result
-                              `((,name . ((base . ,base-versions)
-                                          (target . ,target-versions)))
+                              `((,name . ((base . ,(map car base-versions))
+                                          (target . ,(map car target-versions))))
                                 ,@result)))
                         result)))
                 '()
                 target-versions)))
 
-(define (package-data-other-changes base-packages-vhash target-packages-vhash)
+(define (package-data-derivation-changes base-packages-vhash target-packages-vhash)
   (define base-package-details-by-name-and-version
     (package-data-vhash->package-name-and-version-vhash base-packages-vhash))
 
   (define target-package-details-by-name-and-version
     (package-data-vhash->package-name-and-version-vhash target-packages-vhash))
 
-  (vhash-fold (lambda (name-and-version target-details result)
-                (let ((base-packages-entry
-                       (vhash-assoc name-and-version base-package-details-by-name-and-version)))
-                  (if base-packages-entry
-                      (let ((base-details (cdr base-packages-entry)))
-                        (if (equal? base-details target-details)
-                            result
-                            `((,name-and-version . ((base . ,base-details)
-                                                    (target . ,target-details)))
-                              ,@result)))
-                      result)))
-              '()
-              target-package-details-by-name-and-version))
+  (define (derivation-system-and-target-list->alist lst)
+    (if (null? lst)
+        '()
+        `((,(cdr (first lst)) . ,(car (first lst)))
+          ,@(derivation-system-and-target-list->alist (cdr lst)))))
+
+  (vhash-fold
+   (lambda (name-and-version target-packages-entry result)
+     (let ((base-packages-entry
+            (vhash-assoc name-and-version
+                         base-package-details-by-name-and-version)))
+       (if base-packages-entry
+           (let ((base-derivations (map cdr (cdr base-packages-entry)))
+                 (target-derivations (map cdr target-packages-entry)))
+             (if (equal? base-derivations target-derivations)
+                 result
+                 `((,name-and-version
+                    . ((base . ,(derivation-system-and-target-list->alist
+                                 base-derivations))
+                       (target . ,(derivation-system-and-target-list->alist
+                                   target-derivations))))
+                   ,@result)))
+           result)))
+   '()
+   target-package-details-by-name-and-version))
diff --git a/guix-data-service/jobs/load-new-guix-revision.scm b/guix-data-service/jobs/load-new-guix-revision.scm
index dcdd83e..23044ec 100644
--- a/guix-data-service/jobs/load-new-guix-revision.scm
+++ b/guix-data-service/jobs/load-new-guix-revision.scm
@@ -7,43 +7,104 @@
   #:use-module (guix channels)
   #:use-module (guix inferior)
   #:use-module (guix profiles)
+  #:use-module (guix progress)
   #:use-module (guix packages)
   #:use-module (guix derivations)
   #:use-module (guix build utils)
   #:use-module (guix-data-service model package)
   #:use-module (guix-data-service model guix-revision)
-  #:use-module (guix-data-service model guix-revision-package)
+  #:use-module (guix-data-service model package-derivation)
+  #:use-module (guix-data-service model guix-revision-package-derivation)
   #:use-module (guix-data-service model package-metadata)
   #:use-module (guix-data-service model derivation)
   #:export (process-next-load-new-guix-revision-job
             select-job-for-commit
             most-recent-n-load-new-guix-revision-jobs))
 
-(define (inferior-guix->package-ids store conn inf)
+(define (inferior-guix->package-derivation-ids store conn inf)
+  (define (inferior-package->systems-targets-and-derivations package)
+    (let ((supported-systems
+           (inferior-package-transitive-supported-systems package)))
+      (append-map
+       (lambda (system)
+         (filter-map
+          (lambda (target)
+            (catch
+              #t
+              (lambda ()
+                (list
+                 system
+                 target
+                 (inferior-package-derivation store package system
+                                              #:target
+                                              (if (string=? system target)
+                                                  #f
+                                                  target))))
+              (lambda args
+                (cond
+                 ((string-contains (simple-format #f "~A" (second args))
+                                   "&package-cross-build-system-error")
+                  #f)
+                 ((string-contains (simple-format #f "~A" (fourth args))
+                                   "(No cross-compilation for ")
+                  #f)
+                 (else
+                  (simple-format
+                   #t "guix-data-service: inferior-guix->package-ids: error processing derivation\n  ~A for system ~A and target ~A\n"
+                   package system target)
+                  (for-each (lambda (arg)
+                              (simple-format #t "arg: ~A\n" arg))
+                            args)
+                  #f)))))
+          supported-systems))
+       supported-systems)))
+
   (let* ((packages (inferior-packages inf))
          (packages-metadata-ids
           (inferior-packages->package-metadata-ids conn packages))
-         (packages-derivation-ids
+         (packages-count (length packages))
+         (progress-reporter (progress-reporter/bar
+                             packages-count
+                             (format #f "processing ~a packages"
+                                     packages-count)))
+         (systems-targets-and-derivations-by-package
+          (call-with-progress-reporter progress-reporter
+            (lambda (report)
+              (map
+               (lambda (package)
+                 (report)
+                 (inferior-package->systems-targets-and-derivations package))
+               packages))))
+         (package-ids
+          (inferior-packages->package-ids
+           conn packages packages-metadata-ids))
+         (derivation-ids
           (derivations->derivation-ids
            conn
-           (filter-map
-            (lambda (package)
-              (catch
-                #t
-                (lambda ()
-                  (inferior-package-derivation
-                   store package))
-                (lambda args
-                  (simple-format
-                   #t "guix-data-service: inferior-guix->package-ids: error processing derivation ~A\n"
-                   package)
-                  (simple-format
-                   #t "guix-data-service: inferior-guix->package-ids: error: ~A\n" args)
-                  #f)))
-            packages))))
+           (append-map
+            (lambda (system-targets-and-derivations)
+              (map third system-targets-and-derivations))
+            systems-targets-and-derivations-by-package)))
+         (flat-package-ids-systems-and-targets
+          (append-map
+           (lambda (package-id system-targets-and-derivations)
+             (map (match-lambda
+                    ((system target derivation)
+                     (list package-id
+                           system
+                           target)))
+                  system-targets-and-derivations))
+           package-ids
+           systems-targets-and-derivations-by-package)))
+
+    (insert-package-derivations conn
+                                flat-package-ids-systems-and-targets
+                                derivation-ids)))
 
-    (inferior-packages->package-ids
-     conn packages packages-metadata-ids packages-derivation-ids)))
+(define (inferior-package-transitive-supported-systems package)
+  ((@@ (guix inferior) inferior-package-field)
+   package
+   'package-transitive-supported-systems))
 
 (define (guix-store-path store)
   (let* ((guix-package (@ (gnu packages package-management)
@@ -140,17 +201,21 @@
     (inferior-eval '(use-modules (guix grafts)) inf)
     (inferior-eval '(%graft? #f) inf)
 
-    (let ((package-ids (inferior-guix->package-ids store conn inf)))
-      (exec-query conn "BEGIN")
+    (exec-query conn "BEGIN")
+    (let ((package-derivation-ids
+           (inferior-guix->package-derivation-ids store conn inf))
+          (guix-revision-id
+           (insert-guix-revision conn url commit store_path)))
 
-      (let ((guix-revision-id
-             (insert-guix-revision conn url commit store_path)))
-        (insert-guix-revision-packages conn guix-revision-id package-ids))
+      (insert-guix-revision-package-derivations conn
+                                                guix-revision-id
+                                                package-derivation-ids)
 
       (exec-query conn "COMMIT")
 
       (simple-format
-       #t "Successfully loaded ~A packages\n" (length package-ids)))
+       #t "Successfully loaded ~A package/derivation pairs\n"
+       (length package-derivation-ids)))
 
     (close-inferior inf)))
 
diff --git a/guix-data-service/model/derivation.scm b/guix-data-service/model/derivation.scm
index 305c260..b38efc7 100644
--- a/guix-data-service/model/derivation.scm
+++ b/guix-data-service/model/derivation.scm
@@ -5,16 +5,18 @@
   #:use-module (squee)
   #:use-module (guix base32)
   #:use-module (guix inferior)
+  #:use-module (guix memoization)
   #:use-module (guix derivations)
   #:use-module (guix-data-service model utils)
   #:export (select-derivation-by-file-name
             select-derivation-outputs-by-derivation-id
             select-derivation-by-output-filename
             select-derivations-using-output
+            select-derivations-by-revision-name-and-version
             select-derivation-inputs-by-derivation-id
             select-existing-derivations
             select-derivations-by-id
-            select-derivations-and-build-status-by-id
+            select-derivations-and-build-status-by-file-name
             insert-into-derivations
             derivations->derivation-ids))
 
@@ -62,6 +64,36 @@
 
   (exec-query conn query (list output-id)))
 
+(define (select-derivations-by-revision-name-and-version
+         conn revision-commit-hash name version)
+  (define query "
+SELECT derivations.system, package_derivations.target, derivations.file_name,
+  latest_build_status.status
+FROM derivations
+INNER JOIN package_derivations
+  ON derivations.id = package_derivations.derivation_id
+INNER JOIN packages
+  ON package_derivations.package_id = packages.id
+INNER JOIN guix_revision_package_derivations
+  ON package_derivations.id = guix_revision_package_derivations.package_derivation_id
+INNER JOIN guix_revisions
+  ON guix_revision_package_derivations.revision_id = guix_revisions.id
+LEFT OUTER JOIN builds ON derivations.id = builds.derivation_id
+LEFT OUTER JOIN (
+  SELECT DISTINCT ON (internal_build_id) *
+  FROM build_status
+  ORDER BY internal_build_id, status_fetched_at DESC
+) AS latest_build_status
+  ON builds.internal_id = latest_build_status.internal_build_id
+WHERE guix_revisions.commit = $1
+  AND packages.name = $2
+  AND packages.version = $3
+ORDER BY derivations.system DESC,
+         package_derivations.target DESC,
+         derivations.file_name")
+
+  (exec-query conn query (list revision-commit-hash name version)))
+
 (define (insert-derivation-outputs conn
                                    derivation-id
                                    names-and-derivation-outputs)
@@ -166,21 +198,22 @@
     ((result)
      result)))
 
-(define (select-derivation-output-id conn name path)
-  (match (exec-query
-          conn
-          (string-append
-           "SELECT derivation_outputs.id FROM derivation_outputs "
-           "INNER JOIN derivations ON "
-           "derivation_outputs.derivation_id = derivations.id "
-           "WHERE derivations.file_name = '" path "' "
-           "AND derivation_outputs.name = '" name "';"))
-    (((id))
-     id)
-    (()
-     (error (simple-format
-             #f "cannot find derivation-output with name ~A and path ~A"
-             name path)))))
+(define select-derivation-output-id
+  (mlambda (conn name path)
+    (match (exec-query
+            conn
+            (string-append
+             "SELECT derivation_outputs.id FROM derivation_outputs "
+             "INNER JOIN derivations ON "
+             "derivation_outputs.derivation_id = derivations.id "
+             "WHERE derivations.file_name = '" path "' "
+             "AND derivation_outputs.name = '" name "';"))
+      (((id))
+       id)
+      (()
+       (error (simple-format
+               #f "cannot find derivation-output with name ~A and path ~A"
+               name path))))))
 
 (define (select-derivation-outputs-by-derivation-id conn id)
   (define query
@@ -211,7 +244,7 @@
 
   (exec-query conn query (list id)))
 
-(define (insert-derivation-input conn derivation-id derivation-input)
+(define (insert-derivation-inputs conn derivation-id derivation-inputs)
   (define (insert-into-derivation-inputs output-ids)
     (string-append "INSERT INTO derivation_inputs "
                    "(derivation_id, derivation_output_id) VALUES "
@@ -224,16 +257,19 @@
                     ",")
                    ";"))
 
-  (match derivation-input
-    (($ <derivation-input> path sub-derivations)
-     (exec-query
-      conn
-      (insert-into-derivation-inputs
-       (map (lambda (sub-derivation)
-              (select-derivation-output-id conn
-                                           sub-derivation
-                                           path))
-            sub-derivations))))))
+  (unless (null? derivation-inputs)
+    (exec-query
+     conn
+     (insert-into-derivation-inputs
+      (append-map
+       (match-lambda
+         (($ <derivation-input> path sub-derivations)
+          (map (lambda (sub-derivation)
+                 (select-derivation-output-id conn
+                                              sub-derivation
+                                              path))
+               sub-derivations)))
+       derivation-inputs)))))
 
 (define (select-from-derivation-source-files store-paths)
   (string-append
@@ -304,7 +340,34 @@
     (exec-query conn
                 (insert-into-derivation-sources sources-ids))))
 
-(define (insert-missing-derivations conn derivations)
+(define (insert-missing-derivations conn
+                                    derivation-ids-hash-table
+                                    derivations)
+  (define (ensure-input-derivations-exist input-derivation-file-names)
+    (unless (null? input-derivation-file-names)
+      (simple-format
+       #t "debug: ensure-input-derivations-exist: processing ~A derivations\n"
+       (length input-derivation-file-names))
+      (force-output)
+      (let* ((existing-derivation-entries
+              (derivation-file-names->vhash conn
+                                            derivation-ids-hash-table
+                                            input-derivation-file-names))
+
+             (missing-derivations-filenames
+              (filter (lambda (derivation-file-name)
+                        (not (vhash-assoc derivation-file-name
+                                          existing-derivation-entries)))
+                      input-derivation-file-names)))
+
+        (unless (null? missing-derivations-filenames)
+          ;; Ensure all the input derivations exist
+          (insert-missing-derivations
+           conn
+           derivation-ids-hash-table
+           (map read-derivation-from-file
+                missing-derivations-filenames))))))
+
   (define (insert-into-derivations)
     (string-append
      "INSERT INTO derivations "
@@ -331,24 +394,60 @@
      " RETURNING id"
      ";"))
 
-  (map (lambda (derivation-id derivation)
-         (insert-derivation-outputs conn
-                                    derivation-id
-                                    (derivation-outputs derivation))
-
-         (insert-derivation-sources conn
-                                    derivation-id
-                                    (derivation-sources derivation))
-
-         (for-each (lambda (derivation-input)
-                     (insert-derivation-input conn
-                                              derivation-id
-                                              derivation-input))
-                   (derivation-inputs derivation))
-
-         derivation-id)
-       (map car (exec-query conn (insert-into-derivations)))
-       derivations))
+  (simple-format
+   #t "debug: insert-missing-derivations: inserting ~A derivations\n"
+   (length derivations))
+  (let ((derivation-ids
+         (map car (exec-query conn (insert-into-derivations)))))
+
+    (simple-format
+     #t "debug: insert-missing-derivations: updating hash table\n")
+    (for-each (lambda (derivation derivation-id)
+                (hash-set! derivation-ids-hash-table
+                           (derivation-file-name derivation)
+                           derivation-id))
+              derivations
+              derivation-ids)
+
+    (simple-format
+     #t "debug: insert-missing-derivations: inserting outputs\n")
+    (for-each (lambda (derivation-id derivation)
+                (insert-derivation-outputs conn
+                                           derivation-id
+                                           (derivation-outputs derivation)))
+              derivation-ids
+              derivations)
+
+    (simple-format
+     #t "debug: insert-missing-derivations: inserting sources\n")
+    (for-each (lambda (derivation-id derivation)
+                (insert-derivation-sources conn
+                                           derivation-id
+                                           (derivation-sources derivation)))
+              derivation-ids
+              derivations)
+
+    (simple-format
+     #t "debug: insert-missing-derivations: ensure-input-derivations-exist\n")
+    (force-output)
+
+    (ensure-input-derivations-exist (deduplicate-strings
+                                     (map derivation-input-path
+                                          (append-map
+                                           derivation-inputs
+                                           derivations))))
+
+    (simple-format
+     #t "debug: insert-missing-derivations: inserting inputs\n")
+    (for-each (lambda (derivation-id derivation)
+                (insert-derivation-inputs conn
+                                          derivation-id
+                                          (derivation-inputs derivation)))
+
+              derivation-ids
+              derivations)
+
+    derivation-ids))
 
 (define (select-derivations-by-id conn ids)
   (define query
@@ -363,10 +462,10 @@
 
   (exec-query conn query))
 
-(define (select-derivations-and-build-status-by-id conn ids)
+(define (select-derivations-and-build-status-by-file-name conn file-names)
   (define query
     (string-append
-     "SELECT derivations.id, derivations.file_name, latest_build_status.status "
+     "SELECT derivations.file_name, latest_build_status.status "
      "FROM derivations "
      "LEFT OUTER JOIN builds ON derivations.id = builds.derivation_id "
      "LEFT OUTER JOIN "
@@ -375,60 +474,124 @@
      "ORDER BY internal_build_id, status_fetched_at DESC"
      ") AS latest_build_status "
      "ON builds.internal_id = latest_build_status.internal_build_id "
-     "WHERE derivations.id IN "
-     "(" (string-join (map (lambda (id)
-                             (simple-format #f "'~A'" id))
-                           ids)
+     "WHERE derivations.file_name IN "
+     "(" (string-join (map (lambda (file-name)
+                             (simple-format #f "'~A'" file-name))
+                           file-names)
                       ",")
      ");"))
 
   (exec-query conn query))
 
-(define (derivations->derivation-ids conn derivations)
-  (define (ensure-input-derivations-exist)
-    (let* ((missing-derivation-file-names (map derivation-file-name
-                                               derivations))
-
-           (input-derivation-file-names (delete-duplicates
-                                         (map derivation-input-path
-                                              (append-map
-                                               derivation-inputs
-                                               derivations)))))
-
-      ;; Ensure all the input derivations exist
-      (derivations->derivation-ids
-       conn
-       (map read-derivation-from-file
-            input-derivation-file-names))))
+(define (deduplicate-strings strings)
+  (pair-fold
+   (lambda (pair result)
+     (if (null? (cdr pair))
+         (cons (first pair) result)
+         (if (string=? (first pair) (second pair))
+             result
+             (cons (first pair) result))))
+   '()
+   (sort strings
+         (lambda (a b)
+           (string<? a b)))))
+
+(define (deduplicate-derivations derivations)
+  (define sorted-derivations
+    (sort derivations
+          (lambda (a b)
+            (string<? (derivation-file-name a)
+                      (derivation-file-name b)))))
+
+  (pair-fold
+   (match-lambda*
+     (((x) result)
+      (cons x result))
+     (((x y rest ...) result)
+      (if (string=? (derivation-file-name x)
+                    (derivation-file-name y))
+          result
+          (cons x result))))
+   '()
+   sorted-derivations))
+
+(define (derivation-file-names->vhash conn derivation-ids-hash-table file-names)
+  (simple-format #t "debug: derivation-file-names->vhash: ~A file-names\n"
+                 (length file-names))
+  (match (fold (match-lambda*
+                 ((file-name (result . missing-file-names))
+                  (let ((cached-id (hash-ref derivation-ids-hash-table
+                                             file-name)))
+                    (if cached-id
+                        (cons (vhash-cons file-name cached-id result)
+                              missing-file-names)
+                        (cons result
+                              (cons file-name missing-file-names))))))
+               (cons vlist-null '())
+               file-names)
+    ((result)
+     (simple-format
+      #t "debug: derivation-file-names->vhash: lookup ~A file-names, all found\n"
+      (length file-names))
+     result)
+    ((result . missing-file-names)
+     (simple-format
+      #t "debug: derivation-file-names->vhash: lookup ~A file-names, ~A not cached\n"
+      (length file-names) (length missing-file-names))
+     (let ((result-for-missing-file-names
+            (exec-query->vhash
+             conn
+             (select-existing-derivations missing-file-names)
+             second ;; file_name
+             first))) ;; id
+       (simple-format
+        #t "debug: derivation-file-names->vhash: adding ~A entries to the cache\n"
+        (vlist-length result-for-missing-file-names))
+       (vhash-fold (lambda (key value _)
+                     (hash-set! derivation-ids-hash-table key value))
+                   '()
+                   result-for-missing-file-names)
+
+       (vhash-fold
+        (lambda (key value combined)
+          (vhash-cons key value combined))
+        result
+        result-for-missing-file-names)))))
 
+(define (derivations->derivation-ids conn derivations)
   (if (null? derivations)
       '()
-      (begin
-        (ensure-input-derivations-exist)
+      (let* ((derivations-count (length derivations))
+             (derivation-ids-hash-table (make-hash-table derivations-count)))
+        (simple-format
+         #t "debug: derivations->derivation-ids: processing ~A derivations\n"
+         derivations-count)
         (let* ((derivation-file-names (map derivation-file-name
                                            derivations))
 
-               (existing-derivation-entries (exec-query->vhash
-                                             conn
-                                             (select-existing-derivations
-                                              derivation-file-names)
-                                             second ;; file_name
-                                             first)) ;; id
+               (existing-derivation-entries
+                (derivation-file-names->vhash conn
+                                              derivation-ids-hash-table
+                                              derivation-file-names))
 
                (missing-derivations
-                (filter (lambda (derivation)
-                          (not (vhash-assoc (derivation-file-name derivation)
-                                            existing-derivation-entries)))
-                        derivations))
+                (deduplicate-derivations
+                 (filter (lambda (derivation)
+                           (not (vhash-assoc (derivation-file-name derivation)
+                                             existing-derivation-entries)))
+                         derivations)))
 
                (new-derivation-entries
                 (if (null? missing-derivations)
                     '()
-                    (insert-missing-derivations conn missing-derivations)))
+                    (insert-missing-derivations conn
+                                                derivation-ids-hash-table
+                                                missing-derivations)))
 
                (new-entries-id-lookup-vhash
                 (two-lists->vhash (map derivation-file-name missing-derivations)
                                   new-derivation-entries)))
+
           (map (lambda (derivation-file-name)
                  (cdr
                   (or (vhash-assoc derivation-file-name
diff --git a/guix-data-service/model/guix-revision-package-derivation.scm b/guix-data-service/model/guix-revision-package-derivation.scm
new file mode 100644
index 0000000..733dad2
--- /dev/null
+++ b/guix-data-service/model/guix-revision-package-derivation.scm
@@ -0,0 +1,20 @@
+(define-module (guix-data-service model guix-revision-package-derivation)
+  #:use-module (squee)
+  #:export (insert-guix-revision-package-derivations))
+
+(define (insert-guix-revision-package-derivations
+         conn guix-revision-id package-derivation-ids)
+  (define insert
+    (string-append "INSERT INTO guix_revision_package_derivations "
+                   "(revision_id, package_derivation_id) "
+                   "VALUES "
+                   (string-join (map (lambda (package-derivation-id)
+                                       (simple-format
+                                        #f "(~A, ~A)"
+                                        guix-revision-id
+                                        package-derivation-id))
+                                     package-derivation-ids)
+                                ", ")
+                   ";"))
+
+  (exec-query conn insert))
diff --git a/guix-data-service/model/guix-revision-package.scm b/guix-data-service/model/guix-revision-package.scm
deleted file mode 100644
index 2f710a4..0000000
--- a/guix-data-service/model/guix-revision-package.scm
+++ /dev/null
@@ -1,19 +0,0 @@
-(define-module (guix-data-service model guix-revision-package)
-  #:use-module (squee)
-  #:export (insert-guix-revision-packages))
-
-(define (insert-guix-revision-packages conn guix-revision-id package-ids)
-  (define insert
-    (string-append "INSERT INTO guix_revision_packages "
-                   "(revision_id, package_id) "
-                   "VALUES "
-                   (string-join (map (lambda (package-id)
-                                       (simple-format
-                                        #f "(~A, ~A)"
-                                        guix-revision-id
-                                        package-id))
-                                     package-ids)
-                                ", ")
-                   ";"))
-
-  (exec-query conn insert))
diff --git a/guix-data-service/model/package-derivation.scm b/guix-data-service/model/package-derivation.scm
new file mode 100644
index 0000000..6e87765
--- /dev/null
+++ b/guix-data-service/model/package-derivation.scm
@@ -0,0 +1,112 @@
+(define-module (guix-data-service model package-derivation)
+  #:use-module (srfi srfi-1)
+  #:use-module (ice-9 vlist)
+  #:use-module (ice-9 match)
+  #:use-module (squee)
+  #:use-module (guix-data-service model utils)
+  #:export (insert-package-derivations
+            count-packages-derivations-in-revision))
+
+(define (insert-missing-package-derivations conn entries)
+  (define query
+    (string-append
+     "INSERT INTO package_derivations "
+     "(package_id, derivation_id, system, target) VALUES "
+     (string-join
+      (map
+       (lambda (entry)
+         (apply simple-format
+                #f "(~A, ~A, '~A', '~A')"
+                entry))
+       entries)
+      ", ")
+     " RETURNING id"))
+
+  (exec-query conn query))
+
+(define (insert-package-derivations conn
+                                    package-ids-systems-and-targets
+                                    derivation-ids)
+  (define select-existing-package-derivation-entries
+    (string-append
+     "SELECT id, package_derivations.package_id,"
+     " package_derivations.derivation_id, package_derivations.system,"
+     " package_derivations.target "
+     "FROM package_derivations "
+     "JOIN (VALUES "
+     (string-join (map (match-lambda*
+                         (((package-id system target) derivation-id)
+                          (simple-format
+                           #f "(~A, ~A, '~A', '~A')"
+                           package-id
+                           derivation-id
+                           system
+                           target)))
+                       package-ids-systems-and-targets
+                       derivation-ids)
+                  ", ")
+     ") AS vals (package_id, derivation_id, system, target) "
+     "ON package_derivations.package_id = vals.package_id "
+     "AND package_derivations.derivation_id = vals.derivation_id "
+     "AND package_derivations.system = vals.system "
+     "AND package_derivations.target = vals.target"))
+
+  (define data-4-tuples
+    (map (match-lambda*
+           (((package-id system target) derivation-id)
+            (list package-id
+                  derivation-id
+                  system
+                  target)))
+         package-ids-systems-and-targets
+         derivation-ids))
+
+  (if (null? data-4-tuples)
+      '()
+      (begin
+        (let* ((existing-entries
+                (exec-query->vhash
+                 conn
+                 select-existing-package-derivation-entries
+                 cdr
+                 first)) ;; id
+
+               (missing-entries
+                (filter (lambda (4-tuple)
+                          (not (vhash-assoc 4-tuple existing-entries)))
+                        data-4-tuples))
+
+               (new-entry-ids
+                (if (null? missing-entries)
+                    '()
+                    (begin
+                      (vlist->list existing-entries)
+                      (insert-missing-package-derivations conn missing-entries))))
+
+               (new-entries-id-lookup-vhash
+                (two-lists->vhash missing-entries
+                                  new-entry-ids)))
+          (map (lambda (4-tuple)
+                 (cdr
+                  (or (vhash-assoc 4-tuple existing-entries)
+                      (vhash-assoc 4-tuple new-entries-id-lookup-vhash)
+                      (error "Missing entry"))))
+               data-4-tuples)))))
+
+(define (count-packages-derivations-in-revision conn commit-hash)
+  (define query
+    "
+SELECT package_derivations.system, package_derivations.target,
+COUNT(DISTINCT package_derivations.derivation_id)
+FROM package_derivations
+WHERE package_derivations.id IN (
+ SELECT guix_revision_package_derivations.package_derivation_id
+ FROM guix_revision_package_derivations
+ INNER JOIN guix_revisions
+   ON guix_revision_package_derivations.revision_id = guix_revisions.id
+ WHERE guix_revisions.commit = $1
+)
+GROUP BY package_derivations.system, package_derivations.target
+ORDER BY package_derivations.system DESC, package_derivations.target DESC")
+
+  (exec-query conn query (list commit-hash)))
diff --git a/guix-data-service/model/package-metadata.scm b/guix-data-service/model/package-metadata.scm
index 429538b..bd6cbe6 100644
--- a/guix-data-service/model/package-metadata.scm
+++ b/guix-data-service/model/package-metadata.scm
@@ -9,6 +9,7 @@
   #:use-module (guix inferior)
   #:use-module (guix-data-service model utils)
   #:export (select-package-metadata
+            select-package-metadata-by-revision-name-and-version
             insert-package-metadata
             inferior-packages->package-metadata-ids))
 
@@ -22,6 +23,29 @@
                               ",")
                  ");"))
 
+(define (select-package-metadata-by-revision-name-and-version
+         conn revision-commit-hash name version)
+  (define query "
+SELECT package_metadata.synopsis, package_metadata.description,
+  package_metadata.home_page
+FROM package_metadata
+INNER JOIN packages
+  ON package_metadata.id = packages.package_metadata_id
+WHERE packages.id IN (
+  SELECT package_derivations.package_id
+  FROM package_derivations
+  INNER JOIN guix_revision_package_derivations
+    ON package_derivations.id =
+    guix_revision_package_derivations.package_derivation_id
+  INNER JOIN guix_revisions
+    ON guix_revision_package_derivations.revision_id = guix_revisions.id
+  WHERE guix_revisions.commit = $1
+)
+  AND packages.name = $2
+  AND packages.version = $3")
+
+  (exec-query conn query (list revision-commit-hash name version)))
+
 (define (insert-package-metadata metadata-rows)
   (string-append "INSERT INTO package_metadata "
                  "(sha1_hash, synopsis, description, home_page) "
diff --git a/guix-data-service/model/package.scm b/guix-data-service/model/package.scm
index b5a38fa..bb01986 100644
--- a/guix-data-service/model/package.scm
+++ b/guix-data-service/model/package.scm
@@ -7,75 +7,93 @@
   #:use-module (guix-data-service model utils)
   #:export (select-existing-package-entries
             select-packages-in-revision
+            count-packages-in-revision
             insert-into-package-entries
             inferior-packages->package-ids))
 
 (define (select-existing-package-entries package-entries)
   (string-append "SELECT id, packages.name, packages.version, "
-                 "packages.package_metadata_id, packages.derivation_id "
+                 "packages.package_metadata_id "
                  "FROM packages "
                  "JOIN (VALUES "
                  (string-join (map (lambda (package-entry)
                                      (apply
                                       simple-format
-                                      #f "('~A', '~A', ~A, ~A)"
+                                      #f "('~A', '~A', ~A)"
                                       package-entry))
                                    package-entries)
                               ", ")
-                 ") AS vals (name, version, package_metadata_id, derivation_id) "
+                 ") AS vals (name, version, package_metadata_id) "
                  "ON packages.name = vals.name AND "
                  "packages.version = vals.version AND "
-                 "packages.package_metadata_id = vals.package_metadata_id AND "
-                 "packages.derivation_id = vals.derivation_id"
-                 ";"))
+                 "packages.package_metadata_id = vals.package_metadata_id"))
 
 (define (select-packages-in-revision conn commit-hash)
   (define query
-    (string-append
-     "SELECT packages.name, packages.version, packages.derivation_id "
-     "FROM packages "
-     "INNER JOIN guix_revision_packages"
-     " ON packages.id = guix_revision_packages.package_id "
-     "INNER JOIN guix_revisions"
-     " ON guix_revision_packages.revision_id = guix_revisions.id "
-     "WHERE guix_revisions.commit = $1 "
-     "ORDER BY packages.name, packages.version"))
+    "
+SELECT packages.name, packages.version, package_metadata.synopsis
+FROM packages
+INNER JOIN package_metadata
+  ON packages.package_metadata_id = package_metadata.id
+WHERE packages.id IN (
+ SELECT package_derivations.package_id
+ FROM package_derivations
+ INNER JOIN guix_revision_package_derivations
+   ON package_derivations.id = guix_revision_package_derivations.package_derivation_id
+ INNER JOIN guix_revisions
+   ON guix_revision_package_derivations.revision_id = guix_revisions.id
+ WHERE guix_revisions.commit = $1
+)
+ORDER BY packages.name, packages.version")
+
+  (exec-query conn query (list commit-hash)))
+
+(define (count-packages-in-revision conn commit-hash)
+  (define query
+    "
+SELECT COUNT(DISTINCT packages.name)
+FROM packages
+WHERE packages.id IN (
+ SELECT package_derivations.package_id
+ FROM package_derivations
+ INNER JOIN guix_revision_package_derivations
+   ON package_derivations.id = guix_revision_package_derivations.package_derivation_id
+ INNER JOIN guix_revisions
+   ON guix_revision_package_derivations.revision_id = guix_revisions.id
+ WHERE guix_revisions.commit = $1
+)")
 
   (exec-query conn query (list commit-hash)))
 
 (define (insert-into-package-entries package-entries)
   (string-append "INSERT INTO packages "
-                 "(name, version, package_metadata_id, derivation_id) VALUES "
+                 "(name, version, package_metadata_id) VALUES "
                  (string-join
                   (map
                    (match-lambda
-                     ((name version package_metadata_id derivation_id)
-                      (simple-format #f "('~A', '~A', ~A, ~A)"
+                     ((name version package_metadata_id)
+                      (simple-format #f "('~A', '~A', ~A)"
                                      name
                                      version
-                                     package_metadata_id
-                                     derivation_id)))
+                                     package_metadata_id)))
                    package-entries)
                   ",")
                  " RETURNING id"
                  ";"))
 
-(define (inferior-packages->package-ids conn packages metadata-ids derivation-ids)
+(define (inferior-packages->package-ids conn packages metadata-ids)
   (define package-entries
-    (map (lambda (package metadata-id derivation-id)
+    (map (lambda (package metadata-id)
            (list (inferior-package-name package)
                  (inferior-package-version package)
-                 metadata-id
-                 derivation-id))
+                 metadata-id))
          packages
-         metadata-ids
-         derivation-ids))
+         metadata-ids))
 
   (let* ((existing-package-entry-ids
           (exec-query->vhash conn
                              (select-existing-package-entries package-entries)
-                             ;; name, version, package_metadata_id and
-                             ;; derivation_id
+                             ;; name, version and package_metadata_id
                              cdr
                              first)) ;;id
          (missing-package-entries
diff --git a/guix-data-service/web/controller.scm b/guix-data-service/web/controller.scm
index 9f436dc..a8dd897 100644
--- a/guix-data-service/web/controller.scm
+++ b/guix-data-service/web/controller.scm
@@ -29,6 +29,8 @@
   #:use-module (guix-data-service comparison)
   #:use-module (guix-data-service model guix-revision)
   #:use-module (guix-data-service model package)
+  #:use-module (guix-data-service model package-derivation)
+  #:use-module (guix-data-service model package-metadata)
   #:use-module (guix-data-service model derivation)
   #:use-module (guix-data-service model build)
   #:use-module (guix-data-service jobs load-new-guix-revision)
@@ -113,16 +115,16 @@
            (version-changes
             (package-data-version-changes base-packages-vhash
                                           target-packages-vhash))
-           (other-changes
-            (package-data-other-changes base-packages-vhash
-                                        target-packages-vhash)))
+           (derivation-changes
+            (package-data-derivation-changes base-packages-vhash
+                                             target-packages-vhash)))
       (cond
        ((eq? content-type 'json)
         (render-json
          `((new-packages . ,new-packages)
            (removed-packages . ,removed-packages)
            (version-changes . ,version-changes)
-           (other-changes . ,other-changes))))
+           (derivation-changes . ,derivation-changes))))
        (else
         (apply render-html
                (compare base-commit
@@ -130,7 +132,7 @@
                         new-packages
                         removed-packages
                         version-changes
-                        other-changes)))))))
+                        derivation-changes)))))))
 
 (define (render-compare/derivations content-type
                                     conn
@@ -138,6 +140,15 @@
                                     base-revision-id
                                     target-commit
                                     target-revision-id)
+  (define (derivations->alist derivations)
+    (map (match-lambda
+           ((file-name buildstatus)
+            `((file_name . ,file-name)
+              (build_status . ,(if (string=? "")
+                                   "unknown"
+                                   buildstatus)))))
+         derivations))
+
   (let-values
       (((base-packages-vhash target-packages-vhash)
         (package-data->package-data-vhashes
@@ -156,9 +167,13 @@
        ((eq? content-type 'json)
         (render-json
          `((base . ((commit . ,base-commit)
-                    (derivations . ,base-derivations)))
+                    (derivations . ,(list->vector
+                                     (derivations->alist
+                                      base-derivations)))))
            (target . ((commit . ,target-commit)
-                      (derivations . ,target-derivations))))))
+                      (derivations . ,(list->vector
+                                       (derivations->alist
+                                        target-derivations))))))))
        (else
         (apply render-html
                (compare/derivations
@@ -174,11 +189,13 @@
                                  target-commit
                                  target-revision-id)
   (define (package-data-vhash->json vh)
-    (vhash-fold (lambda (name data result)
-                  (cons (string-append name "@" (car data))
-                        result))
-                '()
-                vh))
+    (delete-duplicates
+     (vhash-fold (lambda (name data result)
+                   (cons `((name . ,name)
+                           (version . ,(car data)))
+                         result))
+                 '()
+                 vh)))
 
   (let-values
       (((base-packages-vhash target-packages-vhash)
@@ -189,10 +206,14 @@
     (cond
      ((eq? content-type 'json)
       (render-json
-       `((base . ((commit . ,base-commit)
-                  (packages . ,(package-data-vhash->json base-packages-vhash))))
-         (target . ((commit . ,target-commit)
-                    (packages . ,(package-data-vhash->json target-packages-vhash)))))))
+       `((base
+          . ((commit . ,base-commit)
+             (packages . ,(list->vector
+                           (package-data-vhash->json base-packages-vhash)))))
+         (target
+          . ((commit . ,target-commit)
+             (packages . ,(list->vector
+                           (package-data-vhash->json target-packages-vhash))))))))
      (else
       (apply render-html
              (compare/packages
@@ -227,14 +248,16 @@
     (match derivation
       (()
        #f)
-      ((derivation)
+      (derivations
        (apply render-html
               (view-store-item filename
-                               derivation
-                               (match derivation
-                                 ((file-name output-id rest ...)
-                                  (select-derivations-using-output
-                                   conn output-id)))))))))
+                               derivations
+                               (map (lambda (derivation)
+                                      (match derivation
+                                        ((file-name output-id rest ...)
+                                         (select-derivations-using-output
+                                          conn output-id))))
+                                    derivations)))))))
 
 (define (controller request body conn)
   (match-lambda
@@ -249,13 +272,31 @@
     ((GET "revision" commit-hash)
      (apply render-html
             (view-revision commit-hash
-                           (select-packages-in-revision conn
-                                                        commit-hash))))
+                           (count-packages-in-revision conn
+                                                       commit-hash)
+                           (count-packages-derivations-in-revision conn
+                                                                   commit-hash))))
+    ((GET "revision" commit-hash "packages")
+     (apply render-html
+            (view-revision-packages commit-hash
+                                    (select-packages-in-revision
+                                     conn commit-hash))))
     ((GET "revision" commit-hash "package" name version)
      (apply render-html
-            (view-revision-package-and-version commit-hash
-                                               name
-                                               version)))
+            (view-revision-package-and-version
+             commit-hash
+             name
+             version
+             (select-package-metadata-by-revision-name-and-version
+              conn
+              commit-hash
+              name
+              version)
+             (select-derivations-by-revision-name-and-version
+              conn
+              commit-hash
+              name
+              version))))
     ((GET "gnu" "store" filename)
      (if (string-suffix? ".drv" filename)
          (render-derivation conn (string-append "/gnu/store/" filename))
diff --git a/guix-data-service/web/view/html.scm b/guix-data-service/web/view/html.scm
index c7c353a..dcd2f15 100644
--- a/guix-data-service/web/view/html.scm
+++ b/guix-data-service/web/view/html.scm
@@ -23,9 +23,12 @@
   #:use-module (ice-9 match)
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-19)
+  #:use-module (texinfo)
+  #:use-module (texinfo html)
   #:export (index
             view-revision-package-and-version
             view-revision
+            view-revision-packages
             view-builds
             view-derivation
             view-store-item
@@ -171,7 +174,9 @@
                        (td ,source))))
                   queued-guix-revisions)))))))))
 
-(define (view-revision-package-and-version revision-commit-hash name version)
+(define (view-revision-package-and-version revision-commit-hash name version
+                                           package-metadata
+                                           derivations)
   (layout
    #:extra-headers
    '((cache-control . ((max-age . 60))))
@@ -181,9 +186,48 @@
       (@ (class "container"))
       (div
        (@ (class "row"))
-       (h1 "Package " ,name " @ " ,version))))))
+       (h3 (a (@ (href ,(string-append
+                         "/revision/" revision-commit-hash)))
+              "Revision " (samp ,revision-commit-hash))))
+      (div
+       (@ (class "row"))
+       (h1 "Package " ,name " @ " ,version))
+      (div
+       (@ (class "row"))
+       ,(match package-metadata
+          (((synopsis description home-page))
+           `(dl
+             (@ (class "dl-horizontal"))
+             (dt "Synopsis")
+             (dd ,(stexi->shtml (texi-fragment->stexi synopsis)))
+             (dt "Description")
+             (dd ,(stexi->shtml (texi-fragment->stexi description)))
+             (dt "Home page")
+             (dd (a (@ (href ,home-page))
+                    ,home-page))))))
+      (div
+       (@ (class "row"))
+       (table
+        (@ (class "table"))
+        (thead
+         (tr
+          (th "System")
+          (th "Target")
+          (th "Derivation")
+          (th "Build status")))
+        (tbody
+         ,@(map
+            (match-lambda
+              ((system target file-name status)
+               `(tr
+                 (td (samp ,system))
+                 (td (samp ,target))
+                 (td (a (@ (href ,file-name))
+                        ,(display-store-item-short file-name)))
+                 (td ,(build-status-span status)))))
+            derivations))))))))
 
-(define (view-revision commit-hash packages)
+(define (view-revision commit-hash packages-count derivations-count)
   (layout
    #:extra-headers
    '((cache-control . ((max-age . 60))))
@@ -196,23 +240,78 @@
        (h1 "Revision " (samp ,commit-hash)))
       (div
        (@ (class "row"))
-       (h3 "Packages")
+       (div
+        (@ (class "col-md-6"))
+        (h3 "Packages")
+        (strong (@ (class "text-center")
+                   (style "font-size: 2em; display: block;"))
+                ,packages-count)
+        (a (@ (class "btn btn-default btn-lg")
+              (href ,(string-append "/revision/" commit-hash
+                                    "/packages")))
+           "View packages"))
+       (div
+        (@ (class "col-md-6"))
+        (h3 "Derivations")
+        (table
+         (@ (class "table"))
+         (thead
+          (tr
+           (th "System")
+           (th "Target")
+           (th "Distinct derivations")))
+         (tbody
+          ,@(map (match-lambda
+                   ((system target count)
+                    (if (string=? system target)
+                        `(tr
+                          (td (@ (class "text-center")
+                                 (colspan 2))
+                              (samp ,system))
+                          (td (samp ,count)))
+                        `(tr
+                          (td (samp ,system))
+                          (td (samp ,target))
+                          (td (samp ,count))))))
+                 derivations-count)))))))))
+
+(define (view-revision-packages revision-commit-hash packages)
+  (layout
+   #:extra-headers
+   '((cache-control . ((max-age . 60))))
+   #:body
+   `(,(header)
+     (div
+      (@ (class "container"))
+      (div
+       (@ (class "row"))
+       (h3 (a (@ (href ,(string-append
+                         "/revision/" revision-commit-hash)))
+              "Revision " (samp ,revision-commit-hash))))
+      (div
+       (@ (class "row"))
+       (h1 "Packages")
        (table
-        (@ (class "table"))
+        (@ (class "table table-responsive"))
         (thead
          (tr
           (th (@ (class "col-md-3")) "Name")
-          (th (@ (class "col-md-3")) "Version")))
+          (th (@ (class "col-md-3")) "Version")
+          (th (@ (class "col-md-3")) "Synopsis")
+          (th (@ (class "col-md-3")) "")))
         (tbody
          ,@(map
             (match-lambda
-              ((name version rest ...)
+              ((name version synopsis)
                `(tr
-                 (td (a (@ (href ,(string-append
-                                   "/revision/" commit-hash
+                 (td ,name)
+                 (td ,version)
+                 (td ,(stexi->shtml (texi-fragment->stexi synopsis)))
+                 (td (@ (class "text-right"))
+                     (a (@ (href ,(string-append
+                                   "/revision/" revision-commit-hash
                                    "/package/" name "/" version)))
-                        ,name))
-                 (td ,version))))
+                        "More information")))))
             packages))))))))
 
 (define (view-builds stats builds)
@@ -237,7 +336,7 @@
             (match-lambda
               ((status count)
                `(tr
-                 (td ,status)
+                 (td ,(build-status-span status))
                  (td ,count))))
             stats))))
       (div
@@ -257,13 +356,8 @@
               ((build-id build-server-url derivation-file-name
                          status-fetched-at starttime stoptime status)
                `(tr
-                 (td (@ (class ,(cond
-                                 ((string=? status "succeeded")
-                                  "bg-success")
-                                 ((string=? status "failed")
-                                  "bg-danger")
-                                 (else ""))))
-                     ,status)
+                 (td (@ (class "text-center"))
+                     ,(build-status-span status))
                  (td (a (@ (href ,derivation-file-name))
                         ,(display-store-item-short derivation-file-name)))
                  (td ,starttime)
@@ -273,6 +367,31 @@
                         "View build on " ,build-server-url)))))
             builds))))))))
 
+(define (build-status-span status)
+  `(span (@ (class ,(string-append
+                     "label label-"
+                     (assoc-ref
+                      '(("scheduled" . "info")
+                        ("started" . "primary")
+                        ("succeeded" . "success")
+                        ("failed" . "danger")
+                        ("failed-dependency" . "warning")
+                        ("failed-other" . "danger")
+                        ("canceled" . "default")
+                        ("" . "default"))
+                      status)))
+            (style "display: inline-block; font-size: 1.2em; margin-top: 0.4em;"))
+         ,(assoc-ref
+           '(("scheduled" . "Scheduled")
+             ("started" . "Started")
+             ("succeeded" . "Succeeded")
+             ("failed" . "Failed")
+             ("failed-dependency" . "Failed (dependency)")
+             ("failed-other" . "Failed (other)")
+             ("canceled" . "Canceled")
+             ("" . "Unknown"))
+           status)))
+
 (define (display-store-item-short item)
   `((span (@ (style "font-size: small; font-family: monospace; display: block;"))
           ,(string-take item 44))
@@ -280,9 +399,9 @@
           ,(string-drop item 44))))
 
 (define (display-store-item item)
-  `((span (@ (style "font-size: small; font-family: monospace;"))
+  `((span (@ (style "font-size: small; font-family: monospace; white-space: nowrap;"))
           ,(string-take item 44))
-    (span (@ (style "font-size: x-large; font-family: monospace;"))
+    (span (@ (style "font-size: x-large; font-family: monospace; white-space: nowrap;"))
           ,(string-drop item 44))))
 
 (define (display-store-item-title item)
@@ -300,7 +419,7 @@
        ,(string-append
          "/" (string-join fileparts "/"))))))
 
-(define (view-store-item filename derivation derivations-using-store-item)
+(define (view-store-item filename derivations derivations-using-store-item-list)
   (layout
    #:extra-headers
    '((cache-control . ((max-age . 60))))
@@ -311,28 +430,31 @@
       (div
        (@ (class "row"))
        ,(display-store-item-title filename))
-      (div
-       (@ (class "row"))
-       (h4 "Derivation: ")
-       ,(match derivation
-          ((file-name output-id)
-           `(a (@ (href ,file-name))
-               ,(display-store-item file-name)))))
-      (div
-       (@ (class "row"))
-       (h2 "Derivations using this store item "
-           ,(let ((count (length derivations-using-store-item)))
-              (if (eq? count 100)
-                  "(> 100)"
-                  (simple-format #f "(~A)" count))))
-       (ul
-        (@ (class "list-unstyled"))
-        ,(map
-          (match-lambda
-            ((file-name)
-             `(li (a (@ (href ,file-name))
-                     ,(display-store-item file-name)))))
-          derivations-using-store-item)))))))
+      ,@(map (lambda (derivation derivations-using-store-item)
+               `((div
+                  (@ (class "row"))
+                  (h4 "Derivation: ")
+                  ,(match derivation
+                     ((file-name output-id)
+                      `(a (@ (href ,file-name))
+                          ,(display-store-item file-name)))))
+                 (div
+                  (@ (class "row"))
+                  (h2 "Derivations using this store item "
+                      ,(let ((count (length derivations-using-store-item)))
+                         (if (eq? count 100)
+                             "(> 100)"
+                             (simple-format #f "(~A)" count))))
+                  (ul
+                   (@ (class "list-unstyled"))
+                   ,(map
+                     (match-lambda
+                       ((file-name)
+                        `(li (a (@ (href ,file-name))
+                                ,(display-store-item file-name)))))
+                     derivations-using-store-item)))))
+             derivations
+             derivations-using-store-item-list)))))
 
 (define (view-derivation derivation derivation-inputs derivation-outputs
                          builds)
@@ -381,17 +503,22 @@
                 (td "System")
                 (td (samp ,system)))))))
         (h3 "Build status")
-        ,@(map
-           (match-lambda
-             ((build-id build-server-url status-fetched-at
-                        starttime stoptime status)
-              `(div
-                (@ (class "text-center"))
-                (div ,status)
-                (a (@ (href ,(simple-format
-                              #f "~Abuild/~A" build-server-url build-id)))
-                   "View build on " ,build-server-url))))
-           builds))
+        ,@(if (null? builds)
+              `((div
+                 (@ (class "text-center"))
+                 ,(build-status-span "")))
+              (map
+               (match-lambda
+                 ((build-id build-server-url status-fetched-at
+                            starttime stoptime status)
+                  `(div
+                    (@ (class "text-center"))
+                    (div ,(build-status-span status))
+                    (a (@ (style "display: inline-block; margin-top: 0.4em;")
+                          (href ,(simple-format
+                                  #f "~Abuild/~A" build-server-url build-id)))
+                       "View build on " ,build-server-url))))
+               builds)))
        (div
         (@ (class "col-md-4"))
         (h3 "Outputs")
@@ -413,7 +540,7 @@
                  new-packages
                  removed-packages
                  version-changes
-                 other-changes)
+                 derivation-changes)
   (define query-params
     (string-append "?base_commit=" base-commit
                    "&target_commit=" target-commit))
@@ -516,24 +643,61 @@
                   version-changes)))))
       (div
        (@ (class "row"))
-       (h3 "Other changed packages")
-       ,@(if (null? other-changes)
-             '((p "No other changes"))
-             `((p "The metadata or derivation for these packages has changed.")
-               (table
-                (@ (class "table"))
-                (thead
-                 (tr
-                  (th (@ (class "col-md-3")) "Name")
-                  (th (@ (class "col-md-9")) "Version")))
-                (tbody
-                 ,@(map
-                    (match-lambda
-                      (((name . version) . (metadata-id derivation-id))
-                       `(tr
-                         (td ,name)
-                         (td ,version))))
-                    other-changes))))))))))
+       (h3 "Package derivation changes")
+       ,(if
+         (null? derivation-changes)
+         '(p "No derivation changes")
+         `(table
+           (@ (class "table")
+              (style "table-layout: fixed;"))
+           (thead
+            (tr
+             (th "Name")
+             (th "Version")
+             (th "System")
+             (th "Target")
+             (th (@ (class "col-xs-5")) "Derivations")))
+           (tbody
+            ,@(append-map
+               (match-lambda
+                 (((name . version) . (('base . base-derivations)
+                                       ('target . target-derivations)))
+                  (let* ((system-and-versions
+                          (delete-duplicates
+                           (append (map car base-derivations)
+                                   (map car target-derivations))))
+                         (data-columns
+                          (map
+                           (lambda (system-and-target)
+                             (let ((base-derivation-file-name
+                                    (assoc-ref base-derivations system-and-target))
+                                   (target-derivation-file-name
+                                    (assoc-ref target-derivations system-and-target)))
+                               `((td (samp (@ (style "white-space: nowrap;"))
+                                           ,(car system-and-target)))
+                                 (td (samp (@ (style "white-space: nowrap;"))
+                                           ,(cdr system-and-target)))
+                                 (td (a (@ (style "display: block;")
+                                           (href ,base-derivation-file-name))
+                                        (span (@ (class "text-danger glyphicon glyphicon-minus pull-left")
+                                                 (style "font-size: 1.5em; padding-right: 0.4em;")))
+                                        ,(display-store-item-short base-derivation-file-name))
+                                     (a (@ (style "display: block;")
+                                           (href ,target-derivation-file-name))
+                                        (span (@ (class "text-success glyphicon glyphicon-plus pull-left")
+                                                 (style "font-size: 1.5em; padding-right: 0.4em;")))
+                                        ,(display-store-item-short target-derivation-file-name))))))
+                           system-and-versions)))
+
+                    `((tr (td (@ (rowspan , (length system-and-versions)))
+                              ,name)
+                          (td (@ (rowspan , (length system-and-versions)))
+                              ,version)
+                          ,@(car data-columns))
+                      ,@(map (lambda (data-row)
+                               `(tr ,data-row))
+                             (cdr data-columns))))))
+               derivation-changes)))))))))
 
 (define (compare/derivations base-commit
                              target-commit
@@ -575,11 +739,11 @@
         (tbody
          ,@(map
             (match-lambda
-              ((id file-name build-status)
+              ((file-name build-status)
                `(tr
                  (td (a (@ (href ,file-name))
                         ,(display-store-item file-name)))
-                 (td ,build-status))))
+                 (td ,(build-status-span build-status)))))
             base-derivations))))
       (div
        (@ (class "row"))
@@ -596,11 +760,11 @@
         (tbody
          ,@(map
             (match-lambda
-              ((id file-name build-status)
+              ((file-name build-status)
                `(tr
                  (td (a (@ (href ,file-name))
                         ,(display-store-item file-name)))
-                 (td ,build-status))))
+                 (td ,(build-status-span build-status)))))
             target-derivations))))))))
 
 (define (compare/packages base-commit
@@ -638,16 +802,25 @@
         (@ (class "table"))
         (thead
          (tr
-          (th (@ (class "col-md-6")) "Name")
-          (th (@ (class "col-md-6")) "Version")))
+          (th (@ (class "col-md-4")) "Name")
+          (th (@ (class "col-md-4")) "Version")
+          (th (@ (class "col-md-4")) "")))
         (tbody
          ,@(map
             (match-lambda
-              ((name version rest ...)
+              ((name version)
                `(tr
                  (td ,name)
-                 (td ,version))))
-            (vlist->list base-packages-vhash)))))
+                 (td ,version)
+                 (td (@ (class "text-right"))
+                     (a (@ (href ,(string-append
+                                   "/revision/" base-commit
+                                   "/package/" name "/" version)))
+                        "More information")))))
+            (delete-duplicates
+             (map (lambda (data)
+                    (take data 2))
+                  (vlist->list base-packages-vhash)))))))
       (div
        (@ (class "row"))
        (h3 "Target ("
@@ -658,16 +831,25 @@
         (@ (class "table"))
         (thead
          (tr
-          (th (@ (class "col-md-6")) "Name")
-          (th (@ (class "col-md-6")) "Version")))
+          (th (@ (class "col-md-4")) "Name")
+          (th (@ (class "col-md-4")) "Version")
+          (th (@ (class "col-md-4")) "")))
         (tbody
          ,@(map
             (match-lambda
-              ((name version rest ...)
+              ((name version)
                `(tr
                  (td ,name)
-                 (td ,version))))
-            (vlist->list target-packages-vhash)))))))))
+                 (td ,version)
+                 (td (@ (class "text-right"))
+                     (a (@ (href ,(string-append
+                                   "/revision/" base-commit
+                                   "/package/" name "/" version)))
+                        "More information")))))
+            (delete-duplicates
+             (map (lambda (data)
+                    (take data 2))
+                  (vlist->list target-packages-vhash)))))))))))
 
 (define (compare-unknown-commit base-commit target-commit
                                 base-exists? target-exists?