03/07: install: Really overwrite TARGET/var/guix/profiles/system-1-link.

[Ludovic Courtès]

civodul pushed a commit to branch master
in repository guix.

commit aea9b23213b097eb689fdae1e8e9577bf71ebb8d
Author: Ludovic Courtès <address@hidden>
Date:   Wed Jun 10 10:25:56 2015 +0200

    install: Really overwrite TARGET/var/guix/profiles/system-1-link.
    
    * gnu/build/install.scm (populate-root-file-system): Delete system-1-link
      under TARGET, not under /.  Use 'catch' and check for EEXIST instead of
      (false-if-exception (delete-file ...)).
---
 gnu/build/install.scm |   16 +++++++++++++---
 1 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/gnu/build/install.scm b/gnu/build/install.scm
index 76536da..32fbe8e 100644
--- a/gnu/build/install.scm
+++ b/gnu/build/install.scm
@@ -133,9 +133,19 @@ includes /etc, /var, /run, /bin/sh, etc., and all the 
symlinks to SYSTEM."
             (directives (%store-directory)))
 
   ;; Add system generation 1.
-  (false-if-exception (delete-file "/var/guix/profiles/system-1-link"))
-  (symlink system
-           (string-append target "/var/guix/profiles/system-1-link")))
+  (let ((generation-1 (string-append target
+                                     "/var/guix/profiles/system-1-link")))
+    (let try ()
+      (catch 'system-error
+        (lambda ()
+          (symlink system generation-1))
+        (lambda args
+          ;; If GENERATION-1 already exists, overwrite it.
+          (if (= EEXIST (system-error-errno args))
+              (begin
+                (delete-file generation-1)
+                (try))
+              (apply throw args)))))))
 
 (define (reset-timestamps directory)
   "Reset the timestamps of all the files under DIRECTORY, so that they appear