font finding in OSX produces 200+ lines of warnings

[tacaswell]

          @anntzer, on my macos 10.15.7 Catalina

system_profiler -xml SPFontsDataType  2>&1    # <- def _get_macos_fonts() in mpl 3.9.0

💥

2024-05-17 11:56:24.964 system_profiler[1061:15889] CoreText note: Client requested name ".AlBayanPUA", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].
2024-05-17 11:56:24.964 system_profiler[1061:15889] CoreText note: Set a breakpoint on CTFontLogSystemFontNameRequest to debug.
2024-05-17 11:56:24.968 system_profiler[1061:15889] CoreText note: Client requested name ".AlBayanPUA-Bold", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].
2024-05-17 11:56:24.972 system_profiler[1061:15889] CoreText note: Client requested name ".AlNilePUA", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].
2024-05-17 11:56:24.975 system_profiler[1061:15889] CoreText note: Client requested name ".AlNilePUA-Bold", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].
2024-05-17 11:56:24.978 system_profiler[1061:15889] CoreText note: Client requested name ".AlTarikhPUA", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].
2024-05-17 11:56:24.982 system_profiler[1061:15889] CoreText note: Client requested name ".AppleColorEmojiUI", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].
2024-05-17 11:56:24.985 system_profiler[1061:15889] CoreText note: Client requested name ".AppleSDGothicNeoI-Regular", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].
2024-05-17 11:56:24.988 system_profiler[1061:15889] CoreText note: Client requested name ".AppleSDGothicNeoI-Medium", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].
2024-05-17 11:56:24.991 system_profiler[1061:15889] CoreText note: Client requested name ".AppleSDGothicNeoI-Light", it will get Times-Roman rather than the intended font. All system UI font access should be through proper APIs such as CTFontCreateUIFontForLanguage() or +[NSFont systemFontOfSize:].
...

200-odd such lines.
So I reinstalled matplotlib==3.8.4.
Please advise: are there functions in font_manager.py I can call to help debug this
or caches / .jsons I can delete ? Thanks

Originally posted by @denis-bz in #27230 (comment)

[denis-bz]

Should the title be "font finding in OSX 10.15 ..." ?
MacOS_version_history says it's an "old version", not even "Older version, still maintained".
(Is there info on macos-versions-tested someplace ? Oughta be in METADATA.)

[tacaswell]

Do we know it is osx version specific?

[jklymak]

This does not happen for 14.x (Sonoma). Catalina is quite old - not sure when the difference would have come in.

[denis-bz]

edit Sunday 19 May:
Folks,
until this is reproduced on other Macos versions, I'd drop it to low low priority --
better things to do than try to decipher these murky error messages (I got nowhere).
A workaround that works for me is to just ignore stderr in
font_manager.py _get_macos_fonts, instead of check_output --

@lru_cache
def _get_macos_fonts():
    p = subprocess.Popen( "system_profiler -xml SPFontsDataType" .split(),
            stdout=subprocess.PIPE, stderr=subprocess.DEVNULL, text=False )
    d, = plistlib.loads( p.stdout.read() )  # not load( p.stdout )    
    items = [Path(entry["path"]) for entry in d["_items"]]
    # print( "▄ bp _get_macos_fonts", len(items) );  breakpoint()
    return items

[anntzer]

Unfortunately I can't repro this on any of the macos versions present on GHA (which start at macos11). I suspect that the practical solution is indeed to silently ignore errors from system_profiler, at least when stdout is valid xml (i.e. we can assume that we'll still get a useful list of fonts from it).