guix: build: ruby-build-system: Install to the vendor directory

* guix/build/ruby-build-system.scm (install): Install gems to the vendor
  directory, rather than the GEM_HOME. The vendor directory does not include
  the version of ruby used to install the gem in the path, which makes it
  easier to add it to the GEM_PATH for all versions of ruby to use.
  (gem-home): Remove procedure.
* gnu/packages/ruby.scm (ruby, ruby-2.1)[native-search-paths]: Switch to
  lib/ruby/vendor_ruby.
  (ruby-1.8)[native-search-paths]: Remove native-search-paths.
  (gem-directory): Remove procedure.
  (ruby-ansi, ruby-ae)[arguments]: Remove use of gem-directory.
  (ruby-metaclass, ruby-instantiator, ruby-introspection, ruby-mocha,
  ruby-nokogiri, ruby-minitest-tu-shim, ruby-redcloth)[arguments]: Remove use
  of gem-home.
  (ruby-git, ruby-httpclient)[arguments]: Remove use of GEM_HOME.
* gnu/packages/databases.scm (es-dump-restore)[arguments]: Remove use of
  GEM_HOME.

3 files changed, 56 insertions, 81 deletions

diff --git a/gnu/packages/databases.scm b/gnu/packages/databases.scm
index 86beb762bb..d7bcce44e7 100644
--- a/gnu/packages/databases.scm
+++ b/gnu/packages/databases.scm
@@ -298,10 +298,10 @@ SQL, Key/Value, XML/XQuery or Java Object storage for their data model.")
            (lambda* (#:key outputs #:allow-other-keys)
              (wrap-program (string-append (assoc-ref outputs "out")
                                           "/bin/es_dump_restore")
-               `("GEM_PATH" ":" prefix (,(string-append
-                                          (getenv "GEM_PATH")
-                                          ":"
-                                          (getenv "GEM_HOME")))))
+               `("GEM_PATH" ":" prefix (,(getenv "GEM_PATH")
+                                        ,(string-append
+                                          (assoc-ref outputs "out")
+                                          "/lib/ruby/vendor_ruby"))))
              #t)))))
     (propagated-inputs
      `(("ruby-httpclient" ,ruby-httpclient)
diff --git a/gnu/packages/ruby.scm b/gnu/packages/ruby.scm
index 2741bd6b7d..ab3c077036 100644
--- a/gnu/packages/ruby.scm
+++ b/gnu/packages/ruby.scm
@@ -96,9 +96,7 @@
     (native-search-paths
      (list (search-path-specification
             (variable "GEM_PATH")
-            (files (list (string-append "lib/ruby/gems/"
-                                        (version-major+minor version)
-                                        ".0"))))))
+            (files (list (string-append "lib/ruby/vendor_ruby"))))))
     (synopsis "Programming language interpreter")
     (description "Ruby is a dynamic object-oriented programming language with
 a focus on simplicity and productivity.")
@@ -182,13 +180,7 @@ a focus on simplicity and productivity.")
                             "lib/mkmf.rb"
                             "process.c")
                (("/bin/sh") (which "sh")))
-             #t)))))
-    (native-search-paths
-     (list (search-path-specification
-            (variable "GEM_PATH")
-            (files (list (string-append "lib/ruby/gems/"
-                                        (version-major+minor version)
-                                        ".0"))))))))
+             #t)))))))
 
 (define-public ruby-1.8
   (package (inherit ruby)
@@ -218,11 +210,6 @@ a focus on simplicity and productivity.")
                (("/bin/sh") (which "sh")))
              #t)))))))
 
-(define (gem-directory ruby-version)
-  "Return the relative gem install directory for RUBY-VERSION."
-  (string-append "/lib/ruby/gems/" (version-major+minor ruby-version)
-                 ".0/gems"))
-
 (define-public ruby-highline
   (package
     (name "ruby-highline")
@@ -1322,13 +1309,11 @@ It allows writing tests, checking results and automated testing in Ruby.")
        (modify-phases %standard-phases
          (add-after 'unpack 'add-test-unit-to-search-path
            (lambda* (#:key inputs #:allow-other-keys)
-             (let* ((test-unit (assoc-ref inputs "ruby-test-unit"))
-                    (test-unit-home (gem-home test-unit
-                                              ,(package-version ruby))))
+             (let* ((test-unit (assoc-ref inputs "ruby-test-unit")))
                (substitute* "Rakefile"
                  (("t\\.libs << \"test\"" line)
                   (string-append line "; t.libs << \""
-                                 test-unit-home
+                                 test-unit "/lib/ruby/vendor_ruby"
                                  "/gems/test-unit-"
                                  ,(package-version ruby-test-unit)
                                  "/lib\""))))
@@ -1387,13 +1372,11 @@ as a base class when writing classes that depend upon
        (modify-phases %standard-phases
          (add-after 'unpack 'add-test-unit-to-search-path
            (lambda* (#:key inputs #:allow-other-keys)
-             (let* ((test-unit (assoc-ref inputs "ruby-test-unit"))
-                    (test-unit-home (gem-home test-unit ,(package-version
-                                                          ruby))))
+             (let* ((test-unit (assoc-ref inputs "ruby-test-unit")))
                (substitute* "Rakefile"
                  (("t\\.libs << \"test\"" line)
                   (string-append line "; t.libs << \""
-                                 test-unit-home
+                                 test-unit "/lib/ruby/vendor_ruby"
                                  "/gems/test-unit-"
                                  ,(package-version ruby-test-unit)
                                  "/lib\""))))
@@ -1426,13 +1409,11 @@ knowing anything about the constructor.")
        (modify-phases %standard-phases
          (add-after 'unpack 'add-test-unit-to-search-path
           (lambda* (#:key inputs #:allow-other-keys)
-            (let* ((test-unit (assoc-ref inputs "ruby-test-unit"))
-                   (test-unit-home (gem-home test-unit ,(package-version
-                                                         ruby))))
+            (let* ((test-unit (assoc-ref inputs "ruby-test-unit")))
               (substitute* "Rakefile"
                 (("t\\.libs << \"test\"" line)
                  (string-append line "; t.libs << \""
-                                test-unit-home
+                                test-unit "/lib/ruby/vendor_ruby"
                                 "/gems/test-unit-"
                                 ,(package-version ruby-test-unit)
                                 "/lib\""))))
@@ -1499,13 +1480,11 @@ conversion to (X)HTML.")
        (modify-phases %standard-phases
          (add-after 'unpack 'add-test-unit-to-search-path
           (lambda* (#:key inputs #:allow-other-keys)
-            (let* ((test-unit (assoc-ref inputs "ruby-test-unit"))
-                   (test-unit-home (gem-home test-unit
-                                             ,(package-version ruby))))
+            (let* ((test-unit (assoc-ref inputs "ruby-test-unit")))
               (substitute* "Rakefile"
                 (("t\\.libs << 'test'" line)
                  (string-append line "; t.libs << \""
-                                test-unit-home
+                                test-unit "/lib/ruby/vendor_ruby"
                                 "/gems/test-unit-"
                                 ,(package-version ruby-test-unit)
                                 "/lib\""))))
@@ -1870,9 +1849,10 @@ run as a daemon and to be controlled by simple start/stop/restart commands.")
                       ;; store.
                       (let ((git    (string-append (assoc-ref inputs "git")
                                                    "/bin/git"))
-                            (config (string-append (getenv "GEM_HOME")
-                                                   "/gems/git-" ,version
-                                                   "/lib/git/config.rb")))
+                            (config (string-append
+                                     (assoc-ref outputs "out")
+                                     "/lib/ruby/vendor_ruby/gems/git-"
+                                     ,version "/lib/git/config.rb")))
                         (substitute* (list config)
                           (("'git'")
                            (string-append "'" git "'")))
@@ -2057,13 +2037,11 @@ to reproduce user environments.")
            ;; 'pkg-config' is not included in the GEM_PATH during
            ;; installation, so we add it directly to the load path.
            (lambda* (#:key inputs #:allow-other-keys)
-             (let* ((pkg-config (assoc-ref inputs "ruby-pkg-config"))
-                    (pkg-config-home (gem-home pkg-config
-                                               ,(package-version ruby))))
+             (let* ((pkg-config (assoc-ref inputs "ruby-pkg-config")))
                (substitute* "ext/nokogiri/extconf.rb"
                  (("gem 'pkg-config'.*")
                   (string-append "$:.unshift '"
-                                 pkg-config-home
+                                 pkg-config "/lib/ruby/vendor_ruby"
                                  "/gems/pkg-config-"
                                  ,(package-version ruby-pkg-config)
                                  "/lib'\n"))))
@@ -2470,13 +2448,11 @@ development of Ruby gems.")
        (modify-phases %standard-phases
          (add-after 'unpack 'fix-test-include-path
           (lambda* (#:key inputs #:allow-other-keys)
-             (let* ((minitest (assoc-ref inputs "ruby-minitest-4"))
-                    (minitest-home (gem-home minitest
-                                             ,(package-version ruby))))
+             (let* ((minitest (assoc-ref inputs "ruby-minitest-4")))
                (substitute* "Rakefile"
                  (("Hoe\\.add_include_dirs .*")
                   (string-append "Hoe.add_include_dirs \""
-                                 minitest-home
+                                 minitest "/lib/ruby/vendor_ruby"
                                  "/gems/minitest-"
                                  ,(package-version ruby-minitest-4)
                                  "/lib" "\""))))
@@ -2883,7 +2859,9 @@ alternative to Marshal for Object serialization. ")
           (lambda* (#:key outputs #:allow-other-keys)
             (wrap-program (string-append (assoc-ref outputs "out")
                                          "/bin/redcloth")
-              `("GEM_HOME" ":" prefix (,(getenv "GEM_HOME"))))
+              `("GEM_PATH" ":" prefix (,(string-append
+                                         (assoc-ref outputs "out")
+                                         "/lib/ruby/vendor_ruby"))))
             #t)))))
     (native-inputs
      `(("bundler" ,bundler)
@@ -3737,7 +3715,7 @@ It has built-in support for the legacy @code{cookies.txt} and
            (lambda* (#:key outputs #:allow-other-keys)
              (wrap-program (string-append (assoc-ref outputs "out")
                                           "/bin/httpclient")
-               `("GEM_HOME" ":" prefix (,(getenv "GEM_HOME"))))
+               `("GEM_PATH" ":" prefix (,(getenv "GEM_PATH"))))
              #t)))))
     (native-inputs
      `(("ruby-rack" ,ruby-rack)))
@@ -3780,9 +3758,9 @@ requests either using arguments or with an interactive prompt.")
          (add-before 'validate-runpath 'replace-broken-symlink
            (lambda* (#:key outputs #:allow-other-keys)
              (let* ((out (assoc-ref outputs "out"))
-                    (file (string-append out
-                                         ,(gem-directory (package-version ruby))
-                                         "/ansi-" ,version "/lib/ansi.yml")))
+                    (file (string-append
+                           out "/lib/ruby/vendor_ruby/gems/ansi-"
+                           ,version "/lib/ansi.yml")))
                ;; XXX: This symlink is broken since ruby 2.4.
                ;; https://lists.gnu.org/archive/html/guix-devel/2017-06/msg00034.html
                (delete-file file)
@@ -3980,9 +3958,9 @@ requirement specifications systems like Cucumber.")
          (add-before 'validate-runpath 'replace-broken-symlink
            (lambda* (#:key outputs #:allow-other-keys)
              (let* ((out (assoc-ref outputs "out"))
-                    (file (string-append out
-                                         ,(gem-directory (package-version ruby))
-                                         "/ae-" ,version "/lib/ae.yml")))
+                    (file (string-append
+                           out "/lib/ruby/vendor_ruby/gems/ae-"
+                           ,version "/lib/ae.yml")))
                ;; XXX: This symlink is broken since ruby 2.4.
                ;; https://lists.gnu.org/archive/html/guix-devel/2017-06/msg00034.html
                (delete-file file)
diff --git a/guix/build/ruby-build-system.scm b/guix/build/ruby-build-system.scm
index c2d2766279..e3a8111514 100644
--- a/guix/build/ruby-build-system.scm
+++ b/guix/build/ruby-build-system.scm
@@ -27,8 +27,7 @@
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-26)
   #:export (%standard-phases
-            ruby-build
-            gem-home))
+            ruby-build))
 
 ;; Commentary:
 ;;
@@ -129,40 +128,48 @@ GEM-FLAGS are passed to the 'gem' invokation, if present."
                                          (assoc-ref inputs "ruby"))
                            1))
          (out (assoc-ref outputs "out"))
-         (gem-home (string-append out "/lib/ruby/gems/" ruby-version ".0"))
+         (vendor-dir (string-append out "/lib/ruby/vendor_ruby"))
          (gem-file (first-matching-file "\\.gem$"))
          (gem-file-basename (basename gem-file))
          (gem-name (substring gem-file-basename
                               0
-                              (- (string-length gem-file-basename) 4)))
-         (gem-directory (string-append gem-home "/gems/" gem-name)))
-    (setenv "GEM_HOME" gem-home)
-    (mkdir-p gem-home)
-    (and (apply system* "gem" "install" gem-file
-                "--local" "--ignore-dependencies"
-                ;; Executables should go into /bin, not /lib/ruby/gems.
-                "--bindir" (string-append out "/bin")
-                gem-flags)
+                              (- (string-length gem-file-basename) 4))))
+    (setenv "GEM_VENDOR" vendor-dir)
+    (and (let ((install-succeeded?
+                (zero?
+                 (apply system* "gem" "install" gem-file
+                        "--local" "--ignore-dependencies" "--vendor"
+                        ;; Executables should go into /bin, not
+                        ;; /lib/ruby/gems.
+                        "--bindir" (string-append out "/bin")
+                        gem-flags))))
+           (or install-succeeded?
+               (begin
+                 (simple-format #t "installation failed\n")
+                 (let ((failed-output-dir (string-append (getcwd) "/out")))
+                   (mkdir failed-output-dir)
+                   (copy-recursively out failed-output-dir))
+                 #f)))
          (begin
            ;; Remove the cached gem file as this is unnecessary and contains
            ;; timestamped files rendering builds not reproducible.
-           (let ((cached-gem (string-append gem-home "/cache/" gem-file)))
+           (let ((cached-gem (string-append vendor-dir "/cache/" gem-file)))
              (log-file-deletion cached-gem)
              (delete-file cached-gem))
            ;; For gems with native extensions, several Makefile-related files
            ;; are created that contain timestamps or other elements making
            ;; them not reproducible.  They are unnecessary so we remove them.
-           (if (file-exists? (string-append gem-directory "/ext"))
+           (if (file-exists? (string-append vendor-dir "/ext"))
                (begin
                  (for-each (lambda (file)
                              (log-file-deletion file)
                              (delete-file file))
                            (append
-                            (find-files (string-append gem-home "/doc")
+                            (find-files (string-append vendor-dir "/doc")
                                         "page-Makefile.ri")
-                            (find-files (string-append gem-home "/extensions")
+                            (find-files (string-append vendor-dir "/extensions")
                                         "gem_make.out")
-                            (find-files (string-append gem-directory "/ext")
+                            (find-files (string-append vendor-dir "/ext")
                                         "Makefile")))))
            #t))))
 
@@ -182,13 +189,3 @@ GEM-FLAGS are passed to the 'gem' invokation, if present."
 (define* (ruby-build #:key inputs (phases %standard-phases)
                      #:allow-other-keys #:rest args)
   (apply gnu:gnu-build #:inputs inputs #:phases phases args))
-
-(define (gem-home store-path ruby-version)
-  "Return a string to the gem home directory in the store given a STORE-PATH
-and the RUBY-VERSION used to build that ruby package"
-  (string-append
-   store-path
-   "/lib/ruby/gems/"
-   (regexp-substitute #f
-                      (string-match "^[0-9]+\\.[0-9]+" ruby-version)
-                      0 ".0")))