Previously, most actions would leave the cache as-is because
'guix-environment*' would indirectly call 'exit', and thus its
continuation was never reached.
* guix/scripts/shell.scm (guix-shell): Move call to
'maybe-remove-expired-cache-entries' to EXIT-HOOK.
The previous behavior was confusing: a warning would be printed and
'guix shell' would go on starting an empty environment.
Reported by Tobias Geerinckx-Rice <me@tobias.gr>.
* guix/scripts/shell.scm (auto-detect-manifest): Change "not loading"
case from warning to error.
* tests/guix-shell.sh: Adjust accordingly.
* guix/scripts/shell.scm (hint-directory, hint-file, record-hint)
(hint-given?): New procedures.
(guix-shell): Record and probe the 'shell-check' hint.
shell: Maintain a profile cache.
With this change, running "guix shell" (no arguments) is equivalent to:
guix environment -r ~/.cache/guix/profiles/some-root -l guix.scm
This is the cache miss. On cache hit, it's equivalent to:
guix environment -p ~/.cache/guix/profiles/some-root
... which can run in 0.1s.
* guix/scripts/shell.scm (options-with-caching): New procedure.
(parse-args): Use it.
(%profile-cache-directory): New variable.
(profile-cache-key, profile-cached-gc-root): New procedures.
(show-help, %options): Add '--rebuild-cache'.
(guix-shell)[cache-entries, entry-expiration]: New procedures.
Add call to 'maybe-remove-expired-cache-entries'.
* doc/guix.texi (Invoking guix shell): Document '--rebuild-cache'.
