I have found that inkscape crashes when opening file dialog (File->Open, Save, ...) if sans-serif font is a bitmap font. I did tests with freetype 2.2.[01], fontconfig 2.4.2, pango 1.15.5 and inkscape 4.43 and svn, but this is old bug. I have tracked down using gdb that this happens when application calls 'pango_ft2_font_get_face(pFont)' in function 'font_instance::InitTheFace()' in file 'src/libnrtype/FontInstance.cpp'. This happens not every time but only with bad 'pFont' parameter, so application can start but crashes with 'internal error' when opening file dialog. It doesn't write to console anything usefull. To test this, in file '~/.fonts.conf' add <alias> <family>sans-serif</family> <prefer> <family>Helvetica</family> </prefer> </alias> in '<fontconfig></fontconfig>' section (and chech that 'fc-match sans' says 'Helvetiva').