Comment 4 for bug 521163

Thanks for pointing me at fontconfig-voodoo, that seems to now give the right results for Japanese text. However it seems to do this at the expense of everything else:

without fontconfig-voodoo:
pm215@canth:~/jlptvocab$ fc-match Sans:lang=zh
wqy-zenhei.ttc: "WenQuanYi Zen Hei" "中等"
pm215@canth:~/jlptvocab$ fc-match Sans:lang=ja
wqy-zenhei.ttc: "WenQuanYi Zen Hei" "中等"
pm215@canth:~/jlptvocab$ fc-match Sans
DejaVuSans.ttf: "DejaVu Sans" "Book"

with fontconfig-voodoo -f -s ja_JP:
pm215@canth:~/jlptvocab$ fc-match Sans:lang=zh
VL-PGothic-Regular.ttf: "VL PGothic" "regular"
pm215@canth:~/jlptvocab$ fc-match Sans:lang=ja
VL-PGothic-Regular.ttf: "VL PGothic" "regular"
pm215@canth:~/jlptvocab$ fc-match Sans
VL-PGothic-Regular.ttf: "VL PGothic" "regular"

(In particular, the effect of this is that plain old English text, like the dialog text in gnome-language-selector itself, looks ugly and blurry.)

Isn't it possible to configure fontconfig to give me the right font based on the lang= specification?