1 files changed, 33 insertions, 12 deletions
diff --git a/guix/scripts/system.scm b/guix/scripts/system.scm
index 66ad9192c1..4f1869af38 100644
--- a/guix/scripts/system.scm
+++ b/guix/scripts/system.scm
@@ -95,8 +95,8 @@
   (store-lift show-what-to-build))
 
 
-(define* (copy-closure item target
-                       #:key (log-port (current-error-port)))
+(define* (copy-item item target
+                    #:key (log-port (current-error-port)))
   "Copy ITEM to the store under root directory TARGET and register it."
   (mlet* %store-monad ((refs (references* item)))
     (let ((dest  (string-append target item))
@@ -118,6 +118,18 @@
 
       (return #t))))
 
+(define* (copy-closure item target
+                       #:key (log-port (current-error-port)))
+  "Copy ITEM and all its dependencies to the store under root directory
+TARGET, and register them."
+  (mlet* %store-monad ((refs    (references* item))
+                       (to-copy (topologically-sorted*
+                                 (delete-duplicates (cons item refs)
+                                                    string=?))))
+    (sequence %store-monad
+              (map (cut copy-item <> target #:log-port log-port)
+                   to-copy))))
+
 (define* (install os-drv target
                   #:key (log-port (current-output-port))
                   grub? grub.cfg device)
@@ -136,16 +148,10 @@ When GRUB? is true, install GRUB on DEVICE, using GRUB.CFG."
             (mkdir-p (string-append target (%store-prefix)))
 
             ;; Copy items to the new store.
-            (sequence %store-monad
-                      (map (cut copy-closure <> target #:log-port log-port)
-                           to-copy))))))
+            (copy-closure to-copy target #:log-port log-port)))))
 
   (mlet* %store-monad ((os-dir -> (derivation->output-path os-drv))
-                       (refs      (references* os-dir))
-                       (lst    -> (delete-duplicates (cons os-dir refs)
-                                                     string=?))
-                       (to-copy   (topologically-sorted* lst))
-                       (%         (maybe-copy to-copy)))
+                       (%         (maybe-copy os-dir)))
 
     ;; Create a bunch of additional files.
     (format log-port "populating '~a'...~%" target)
@@ -166,6 +172,16 @@ When GRUB? is true, install GRUB on DEVICE, using GRUB.CFG."
   ;; The system profile.
   (string-append %state-directory "/profiles/system"))
 
+(define-syntax-rule (save-environment-excursion body ...)
+  "Save the current environment variables, run BODY..., and restore them."
+  (let ((env (environ)))
+    (dynamic-wind
+      (const #t)
+      (lambda ()
+        body ...)
+      (lambda ()
+        (environ env)))))
+
 (define* (switch-to-system os
                            #:optional (profile %system-profile))
   "Make a new generation of PROFILE pointing to the directory of OS, switch to
@@ -179,7 +195,11 @@ it atomically, and then run OS's activation script."
       (switch-symlinks profile generation)
 
       (format #t (_ "activating system...~%"))
-      (return (primitive-load (derivation->output-path script)))
+
+      ;; The activation script may change $PATH, among others, so protect
+      ;; against that.
+      (return (save-environment-excursion
+               (primitive-load (derivation->output-path script))))
 
       ;; TODO: Run 'deco reload ...'.
       )))
@@ -293,7 +313,8 @@ actions."
              (mlet %store-monad ((% (switch-to-system os)))
                (when grub?
                  (unless (false-if-exception
-                          (install-grub grub.cfg device "/"))
+                          (install-grub (derivation->output-path grub.cfg)
+                                        device "/"))
                    (leave (_ "failed to install GRUB on device '~a'~%")
                           device)))
                (return #t)))