No, I don't have any features written. Until yesterday test installing worked completly fine. Now, I just amended the design of a letter and test installing doesn't work anymore. I have as well tried to test install previous versions of the font (that I have been installed sucessfully), but it wouldn't test install them anymore.
Thanks a lot for your help!
Or maybe just simplify it to an all-or-nothing operation. That's how it's usually implemented. It's a useful function to have in the file menu, because it's a common need, and it saves some clicking and mousing.
in case it is helpful: it seems like the workaround you provided works with glyphs that contain outlines, but not with glyphs that only contain components (for example accents in my font)
f = CurrentFont()
f['aacute'].selected = True
f['a'].selected = True
the code above, run when all glyphs are shown, will select a but not aacute.