pixi shell Command Doesn't Work With Fish

[zicklag]

Checks

• I have checked that this issue has not already been reported.

• I have confirmed this bug exists on the latest version of pixi, using pixi --version.

Reproducible example

/tmp
➜ cd test/

/tmp/test
➜ pixi shell
 source "/tmp/pixi_env_Tpp.fish"

/tmp/test
➜  source "/tmp/pixi_env_Tpp.fish"
/tmp/pixi_env_Tpp.fish (line 11): $(...) is not supported. In fish, please use '(old_fish_prompt)'.
functions -c fish_prompt old_fish_prompt; function fish_prompt; echo "(test) $(old_fish_prompt)"; end;
                                                                             ^
from sourcing file /tmp/pixi_env_Tpp.fish
source: Error while reading file “/tmp/pixi_env_Tpp.fish”

/tmp/test
➜ tail -n 1 /tmp/pixi_env_Tpp.fish
functions -c fish_prompt old_fish_prompt; function fish_prompt; echo "(test) $(old_fish_prompt)"; end;

/tmp/test
➜ pixi --version
pixi 0.15.1

Issue description

When running pixi shell, I get an error about invalid fish syntax. Running eval (pixi shell-hook) works as expected.

It appears that the issue only happens when setting the prompt, which is not modified by pixi shell-hook, so that's probably why it works.

Expected behavior

I should get a pixi environment shell without an error.

[zicklag]

Just discovered that eval (pixi shell-hook) does not work properly, as it only sets the path. The proper workaround is to run pixi shell-hook | source.

BTW, since I use starship for my shell prompt. This will actually properly display the pixi environment in the propmpt, even though the shell snippet doesn't actually modify the fish prompt explicitly.

[ruben-arts]

Apparently both pixi shell and starship init fish overwrite the function fish_prompt. We should look into how to avoid that overwrite in fish. Maybe @tdejager knows some tricks?

eval "$(pixi shell-hook)" works but the | source is advised as the shell-hook doesn't need stdin