guix package: Use relative symlinks to generations.

Reported by Roel Janssen <roel@gnu.org>
at <https://lists.gnu.org/archive/html/guix-devel/2018-07/msg00036.html>.

* guix/profiles.scm (switch-to-generation): Use (basename generation) as
the symlink target.
* guix/scripts/package.scm (build-and-use-profile): Likewise,
use (basename name) as the symlink target.
* tests/guix-package.sh: Adjust --roll-back test accordingly.  Add
explicitly test with '-p foo/prof'.

1 files changed, 11 insertions, 1 deletions

diff --git a/tests/guix-package.sh b/tests/guix-package.sh
index 3b3fa35cd82..cef3b3452e3 100644
--- a/tests/guix-package.sh
+++ b/tests/guix-package.sh
@@ -185,6 +185,16 @@ grep -E 'emacs[[:blank:]]+42\.5\.9rc7[[:blank:]]+.*-emacs-42.5.9rc7' \
 rm "$emacs_tarball" "$tmpfile"
 rmdir "$module_dir"
 
+# Profiles with a relative file name.  Make sure we don't create dangling
+# symlinks--see bug report at
+# <https://lists.gnu.org/archive/html/guix-devel/2018-07/msg00036.html>.
+mkdir -p "$module_dir/foo"
+( cd "$module_dir" ;                                            \
+  guix package --bootstrap -i guile-bootstrap -p foo/prof )
+test -f "$module_dir/foo/prof/bin/guile"
+rm "$module_dir/foo"/*
+rmdir "$module_dir/foo"
+rmdir "$module_dir"
 
 #
 # Try with the default profile.
@@ -215,7 +225,7 @@ do
     guix package --bootstrap --roll-back
     ! test -f "$HOME/.guix-profile/bin"
     ! test -f "$HOME/.guix-profile/lib"
-    test "`readlink "$default_profile"`" = "$default_profile-0-link"
+    test "`readlink "$default_profile"`" = "`basename $default_profile-0-link`"
 done
 
 # Check whether '-p ~/.guix-profile' makes any difference.