Wired fontconfig behavior

["Wang Xu" <gnawux@gmail.com>]

Hi list,

I set alias of monospace in my ${HOME}/.fonts.conf like this:
 |   <alias>
 |       <family>monospace</family>
 |       <prefer>
 |           <family>Bitstream Vera Sans Mono</family>
 |           <family>FZXiYuan-M01S</family>
 |       </prefer>
 |   </alias>
but with fc-match, I found the latter have a higher position:
 | gnawux@stream:~$ fc-match -s "monospace"|head
 | fzyljw.ttf: "FZXiYuan-M01S" "Regular"
 | VeraMono.ttf: "Bitstream Vera Sans Mono" "Roman"
 | ...

where the FZXiYuan is a Chinese font. Even if I substitute FZXiYuan
with another Chinese fonts and substitute bitstream with another
Lattin fonts, it behaviors like above.

The same thing occured on serif and sans-serif also, however, for
bitstream fonts, it works well, for instance
 |   <alias>
 |       <family>Bitstream Vera Sans Mono</family>
 |       <prefer>
 |           <family>Bitstream Vera Sans Mono</family>
 |           <family>FZXiYuan-M01S</family>
 |       </prefer>
 |   </alias>
and with fc-match:
 | gnawux@stream:~$ fc-match -s "Bitstream Vera Sans Mono"|head
 | VeraMono.ttf: "Bitstream Vera Sans Mono" "Roman"
 | fzyljw.ttf: "FZXiYuan-M01S" "Regular"
 |.....

What's wrong with monospace, sans-serif, and serif?

any ideas?

Thank you!

-- 
Wang Xu