"nix-collect-garbage --help" needs groff

[sokai]

Describe the bug

nix-collect-garbage --help shows 2 error messages (instead of the help text):

1. sh: line 1: nroff: command not found
2. sh: line 1: tbl: command not found

Steps To Solve

Install pkgs.groff (explicit)

Expected behavior

nix-collect-garbage --help should work without installing groff/a new package.

Metadata

nix-env (Nix) 2.24.12

Additional context

I haven't tested it (I'm in hurry, sry), but maybe my config documentation.man.enable = false; is the/a cause …?
And I also have bat + bat-extras.batman installed and have set the Bash alias man = "batman";.

Checklist

• checked latest Nix manual (source)
• checked open bug issues and pull requests for possible duplicates
  • (I looked for groff + tbl w/o luck …)

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[caldetas]

Could not reproduce the error, it may really be a problem with your config..

[roberth]

The nix-* rely on a functioning man command to display a help text.
I find this unfortunate, because a more terse --help text can be more effective when we need to be reminded of syntax but not semantics.
However, changing this would require a rework of the legacy commands, which is an effort that would be better spent on the new nix command, which has more suitable infrastructure in place to generate such a help text.
Furthermore, the nix command already uses a markdown-based renderer that's built into Nix instead of an external dependency like man.

Possible workarounds: fix the ambient man command, or use the nix-command experimental feature.