Possibly incorrect WARN on monospaced build width consistency - some marks have zero advance width definitions

Glyphs source file -> static instance TTF font build with fontmake v2.2.1 pipeline. This is a weight axis monospaced typeface.

Observed behaviour

fontbakery raises a WARN level report that the combining marks *comb glyphs in our glyph set have inconsistent widths in a monospaced typeface.

The report is:

* WARN: Font is monospaced but 9 glyphs (3.91304347826087%) have a different width. You should check the widths of: ['uni0308', 'gravecomb', 'acutecomb', 'uni0302', 'uni030C', 'uni030A', 'tildecomb', 'uni0304', 'uni0327'] [code: mono-outliers]

and this appears to come from this block of the fontbakery source:

https://github.com/googlefonts/fontbakery/blob/42e872c92947569f5972a76bb52175e95666ed08/Lib/fontbakery/profiles/shared_conditions.py#L152-L173

I reviewed the Glyphs source files and the advance width for all of the reported glyphs is set at the expected value for the typeface (600).

Here is what I see in the binaries:

>>> for glyphname, metrics in glyph_metrics.items():
...     if metrics[0] != 600:
...         print(f"{glyphname}: {metrics}")
...
uni0308: (0, 140)
gravecomb: (0, 213)
acutecomb: (0, 213)
uni0302: (0, 146)
uni030C: (0, 146)
uni030A: (0, 190)
tildecomb: (0, 126)
uni0304: (0, 161)
uni0327: (0, 200)

And a visual of dieresiscomb:

It looks like a subset of the marks (maybe all combining marks?) are compiled with a zero advance width value and should be excluded from this check.

Expected behaviour

This is not reported as a warning for monospaced typefaces if these metrics are valid.

[felipesanches]

I’ve just verified that indeed commit 42e872c92947569f5972a76bb52175e95666ed08 (as suggested by @kontur) fixed the problem last month and was included in the last two stable releases, 0.7.30 and 0.7.31

@chrissimpkins please update your fontbakery installation to benefit from the fix.

[chrissimpkins]

Can you please send me some of those files, @chrissimpkins?

Done! Thanks Felipe!