environment: Add '--root' option.

* guix/scripts/environment.scm (show-help, %options): Add --root.
(register-gc-root): New procedure.
(guix-environment): Call 'register-gc-root' when OPTS has a 'gc-root'
option.
* doc/guix.texi (Invoking guix environment): Document it.
* tests/guix-environment.sh: Add tests.

1 files changed, 16 insertions, 1 deletions

diff --git a/tests/guix-environment.sh b/tests/guix-environment.sh
index 68343520b0..2b3bbfe036 100644
--- a/tests/guix-environment.sh
+++ b/tests/guix-environment.sh
@@ -25,7 +25,8 @@ set -e
 guix environment --version
 
 tmpdir="t-guix-environment-$$"
-trap 'rm -r "$tmpdir"' EXIT
+gcroot="t-guix-environment-gc-root-$$"
+trap 'rm -r "$tmpdir"; rm -f "$gcroot"' EXIT
 
 mkdir "$tmpdir"
 
@@ -61,6 +62,20 @@ fi
 guix environment --bootstrap --ad-hoc guile-bootstrap --pure \
      -- "$SHELL" -c 'test -f "$GUIX_ENVIRONMENT/bin/guile"'
 
+# Make sure '-r' works as expected.
+rm -f "$gcroot"
+expected="`guix environment --bootstrap --ad-hoc guile-bootstrap \
+             -- "$SHELL" -c 'echo $GUIX_ENVIRONMENT'`"
+guix environment --bootstrap -r "$gcroot" --ad-hoc guile-bootstrap \
+     -- guile -c 1
+test `readlink "$gcroot"` = "$expected"
+
+# Make sure '-r' is idempotent.
+guix environment --bootstrap -r "$gcroot" --ad-hoc guile-bootstrap \
+     -- guile -c 1
+test `readlink "$gcroot"` = "$expected"
+
+
 case "`uname -m`" in
     x86_64)
 	# On x86_64, we should be able to create a 32-bit environment.