man-db test failures [was: unrecognized X command 'sgr 0' ignored (was: early adopters of] groff 1.23.0)

[Alexis]

Hello Branden,

The NixOS package for groff 1.23.0 is still seeing man-db test-failures
with groff 1.23.0 (https://github.com/NixOS/nixpkgs/pull/241870).

As before the observed test failures on Linux seem to stem from warnings
output by groff, this time about line-breaking:

  man -E UTF-8 -l ./man1/manpath.1 produced error output:
  troff:<standard input>:125: warning [p 2, 0.3i]: cannot break line

(https://github.com/NixOS/nixpkgs/pull/241870#issuecomment-1629784635)


On Darwin (what I'm using) Nixpkgs has the man-db tests for (as of yet)
unknown reasons disabled. Enabling the tests the test failures are not
related to line-breaking as on Linux, but rather about recoding UTF-8
to/from ISO-8859-1 and other encodings.

(https://github.com/NixOS/nixpkgs/pull/241870#issuecomment-1629818306)


At this point I'm uncertain where to best look for a solution.
The questions that arise for me from this are:

  - What causes the warnings to appear with groff 1.23.0?
  - Does ./man1/manpath.1 need changes as to "fix" the line breaks?
  - Should man-db's tests be more lenient in regards to warnings?
  - Is it something specific to NixOS customisations of groff or man-db?
  - What is special about Darwin that the recoding tests fail?
  - Can NixOS pass a flag or set an environment variable to the man-db
    test suite to avoid treating warnings as errors?

Any ideas or help to drive this forward would be greatly appreciated.
And please let me know if this list is the right place for this
conversation or whether it should rather be held elsewhere.


Best,
Alexis