Subject: Re: [PATCH v2] meson: Tolerate errors from git ls-files --deduplicate

From: Patrick Steinhardt <[email-masked]>
Date: Fri, 1 Aug 2025 11:45:29 +0200

On Fri, Aug 01, 2025 at 12:42:52PM +0300, Martin Storsjö wrote:
> On Fri, 1 Aug 2025, Patrick Steinhardt wrote:
> 
> > On Fri, Aug 01, 2025 at 10:56:22AM +0300, Martin Storsjö wrote:
> > > index 9bc1826cb6..9b519e6eed 100644
> > > --- a/meson.build
> > > +++ b/meson.build
> > > @@ -694,9 +694,12 @@ third_party_excludes = [
> > > 
> > >  headers_to_check = []
> > >  if git.found() and fs.exists(meson.project_source_root() / '.git')
> > > -  foreach header : run_command(git, '-C', meson.project_source_root(), 'ls-files', '--deduplicate', '*.h', third_party_excludes, check: true).stdout().split()
> > > -    headers_to_check += header
> > > -  endforeach
> > > +  ls_headers = run_command(git, '-C', meson.project_source_root(), 'ls-files', '--deduplicate', '*.h', third_party_excludes, check: false)
> > > +  if ls_headers.returncode() == 0
> > > +    foreach header : ls_headers.stdout().split()
> > > +      headers_to_check += header
> > > +    endforeach
> > > +  endif
> > >  endif
> > 
> > Yup, this looks reasonable to me. We could have an `else` branch that
> > warns about the command failing, for example like this:
> > 
> >    warning("could not find headers: " + ls_headers.stderr())
> 
> This would work - however the output from ls_headers.stderr() is fairly long
> (if you try running e.g. "git ls-files --foobar", you'll get a 37 line
> listing of potential options); it's rather distracting for what's otherwise
> a fairly minor build configuration issue.
> 
> Using ls_headers.stderr().split('\n')[0] works and just gets us this:
> 
>     ../meson.build:703: WARNING: could not find headers: error: unknown option `deduplicate'
> 
> However I wonder if it's worth it, or if it just makes the meson file
> potentially more brittle? (E.g. what if split() returns an array of 0
> elements? Not sure if that's possible though...)

True. Maybe we can just not include stderr at all but say:

    could not list headers, disabling static analysis targets

That's probably sufficient.

Patrick