[bug#50960] [PATCH 00/10] Add 'guix shell' to subsume 'guix environment'

[Ludovic Courtès]

Hello Guix!

Here comes ‘guix shell’, a proposed replacement for ‘guix environment’!
‘guix environment’ would stay around though, at least for some time,
probably for a long time.

The differences to ‘guix environment’ are:

  1. ‘--ad-hoc’ is the default.

       ‘guix shell hello’ ≍ ‘guix environment --ad-hoc hello’
       ‘guix shell -D hello git’ ≍ ‘guix environment hello --ad-hoc git’

  2. ‘guix shell’, without arguments, loads ‘guix.scm’ or ‘manifest.scm’
     from the current directory or one of its ancestors.

  3. ‘--load’/‘-l’ is not ‘-f’/‘--install-from-file’ for consistency with
     ‘guix package’.

  4. ‘guix shell’ without arguments maintains a cache, such that, the
     second time you run it, it runs in ~0.1s (it does not even need to
     connect to the daemon).

     If you run ‘guix pull’ and run again ‘guix shell’, it recomputes
     the environment, as is currently the case with ‘guix environment’.

Here’s a summary of previous proposals:

  - Dave Thompson: 
https://lists.gnu.org/archive/html/guix-devel/2017-08/msg00300.html
    - [X] --ad-hoc is the default
    - [X] caching
    - [X] behavior with no arguments
    - [ ] --load accepts <environment>
    - [ ] Shepherd services
    - [ ] 'guix environment --update' to explicitly update
  - make --ad-hoc the default: https://issues.guix.gnu.org/38529
    - [X] https://issues.guix.gnu.org/38529#17: proposal for a new subcommand
          deprecation of ‘guix environment’

I think <environment> records and Shepherd services could come later.
As for ‘--update’, I prefer the behavior implemented here because it’s
stateless and thus more predictable.

Thoughts?  Are there other changes people would like to see?

If there’s rough consensus I can work on v2 with documentation.  Please
let’s keep the discussion focused.  :-)

As for deprecation, I think there’s no rush.  I imagine there could be
several phases, like: initially we only mention deprecation in the manual,
later on ‘guix environment’ starts emitting a warning, and later (I guess
at least two years later, probably more) we ask ourselves whether to
remove ‘guix environment’.  At this point keeping it doesn’t cost us much.

Thanks,
Ludo’.

Ludovic Courtès (10):
  packages: Add 'package-development-inputs'.
  profiles: Add 'package->development-manifest'.
  DRAFT Add 'guix shell'.
  DRAFT shell: By default load the local 'guix.scm' or 'manifest.scm'
    file.
  environment: Add tests for '--profile'.
  environment: Skip derivation computation when '--profile' is used.
  environment: Do not connect to the daemon when '--profile' is used.
  environment: Autoload some modules.
  cache: Gracefully handle non-existent cache.
  shell: Maintain a profile cache.

 Makefile.am                         |   2 +
 doc/guix.texi                       |  52 ++++++
 guix/cache.scm                      |  10 +-
 guix/packages.scm                   |  10 ++
 guix/profiles.scm                   |  19 ++
 guix/scripts/environment.scm        | 260 +++++++++++++++-------------
 guix/scripts/shell.scm              | 254 +++++++++++++++++++++++++++
 po/guix/POTFILES.in                 |   1 +
 tests/guix-environment-container.sh |   8 +
 tests/guix-environment.sh           |   7 +
 tests/guix-shell.sh                 |  70 ++++++++
 tests/packages.scm                  |  14 ++
 tests/profiles.scm                  |   7 +
 13 files changed, 594 insertions(+), 120 deletions(-)
 create mode 100644 guix/scripts/shell.scm
 create mode 100644 tests/guix-shell.sh

-- 
2.33.0