guix-package: When rolling back to nothingness, point to the empty profile.

Suggested by Andreas Enge <andreas@enge.fr> at
<http://lists.gnu.org/archive/html/bug-guix/2013-01/msg00316.html>.

* guix-package.in (roll-back): Check whether PROFILE is valid using
  `file-exists?'.  When NUMBER is zero, just emit a notice.  When
  PREVIOUS-NUMBER is zero and PREVIOUS-PROFILE does not exist, build the
  empty profile, and link to it.
* tests/guix-package.sh: Add tests.
* doc/guix.texi (Invoking guix-package): Document the new behavior.
master
Ludovic Courtès 2013-01-27 17:18:55 +01:00
parent 29767aaef6
commit d9307267b3
3 changed files with 39 additions and 11 deletions

View File

@ -509,6 +509,11 @@ the last transaction.
When combined with options such as @code{--install}, roll back occurs
before any other actions.
When rolling back from the first generation that actually contains
installed packages, the profile is made to point to the @dfn{empty
profile}, also known as @dfn{profile zero}---i.e., it contains no files
apart from its own meta-data.
@item --profile=@var{profile}
@itemx -p @var{profile}
Use @var{profile} instead of the user's default profile.

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@ -220,14 +220,26 @@ all of PACKAGES, a list of name/version/output/path tuples."
(symlink previous-profile pivot)
(rename-file pivot profile)))
(cond ((zero? number)
(cond ((not (file-exists? profile)) ; invalid profile
(format (current-error-port)
(_ "error: `~a' is not a valid profile~%")
(_ "error: profile `~a' does not exist~%")
profile))
((or (zero? previous-number)
((zero? number) ; empty profile
(format (current-error-port)
(_ "nothing to do: already at the empty profile~%")))
((or (zero? previous-number) ; going to emptiness
(not (file-exists? previous-profile)))
(leave (_ "error: no previous profile; not rolling back~%")))
(else (switch-link)))))
(let*-values (((drv-path drv)
(profile-derivation (%store) '()))
((prof)
(derivation-output-path
(assoc-ref (derivation-outputs drv) "out"))))
(when (not (build-derivations (%store) (list drv-path)))
(leave (_ "failed to build the empty profile~%")))
(symlink prof previous-profile)
(switch-link)))
(else (switch-link))))) ; anything else
;;;

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@ -81,9 +81,14 @@ then
test "`readlink_base "$profile"`" = "$profile-1-link"
test -x "$profile/bin/guile" && ! test -x "$profile/bin/make"
# Failed attempt to roll back because there's no previous generation.
if guix-package --roll-back -p "$profile";
then false; else true; fi
# Move to the empty profile.
for i in `seq 1 3`
do
guix-package --bootstrap --roll-back -p "$profile"
! test -f "$profile/bin"
! test -f "$profile/lib"
test "`readlink_base "$profile"`" = "$profile-0-link"
done
# Reinstall after roll-back to generation 1.
guix-package --bootstrap -p "$profile" -i "$boot_make"
@ -136,9 +141,15 @@ then
test "`cd $HOME/.guix-profile ; pwd`" = "$first_environment"
fi
# Failed attempt to roll back.
if guix-package --bootstrap --roll-back;
then false; else true; fi
# Move to the empty profile.
default_profile="`readlink "$HOME/.guix-profile"`"
for i in `seq 1 3`
do
guix-package --bootstrap --roll-back
! test -f "$HOME/.guix-profile/bin"
! test -f "$HOME/.guix-profile/lib"
test "`readlink "$default_profile"`" = "$default_profile-0-link"
done
# Extraneous argument.
! guix-package install foo-bar