[builder] `expandFeaturesToInstances` not working

[arrowtype]

In #558, it was reported that features weren’t expanding into instances, which meant that feature includes weren’t working. This seems to have been closed by #617.

However, I’m now experiencing the original issue – even when I add expandFeaturesToInstances: true to my config.

If I dig into the instance_ufos folder, then into a JSON UFO, it starts with this:

{"features":"include(fea/Familyname.fea);"

...where I would expect to see the full features, expanded, rather than the original include() statement.

The build crashes with the error, when attempting to build static OTFs and TTFs:

fontmake: Error: Compiling UFO failed: <features>:1:8: The following feature file should be included but cannot be found: fea/Familyname.fea

However, if I do run fontmake directly on the same designspace, with the arg --expand-features-to-instances, it works just fine.

Am I missing something, or could this be a regression?

[arrowtype]

For a little more detail (which seems to point to the more specific issue), here’s a snippet of the build log:

[227/1410] instantiateUfo
fontmake -i Familyname  Extra Wide Extra Light Italic -o ufo -m sources/ufo/FamilynameItalic.designspace --ufo-structure=json --output-dir sources/ufo/instance_ufos
[228/1410] buildTTF
FAILED: /tmp/tmp8sbi6k_4 
/gftools/bin/python -m gftools.builder.jobrunner fontmake --output-path /tmp/tmp8sbi6k_4 -o ttf -u sources/ufo/instance_ufos/FamilynameExtraCompressed-Hairline.ufo.json --filter ...  --filter FlattenComponentsFilter --filter DecomposeTransformedComponentsFilter --expand-features-to-instances 

The way I’m understanding that, it looks like --expand-features-to-instances is being added too late. It needs to be added to the instantiateUfo process, but instead, it’s added only at the buildTTF / buildOTF stage. I’ll go see whether I can test putting it in the earlier stage...

[arrowtype]

Oh, I already figured this out and made a PR for it in the past.

#985

Would it be possible to merge that? Is there anything blocking it? It would be pretty helpful for my workflow!