我所使用的fontconfig文件（~/.config/fontconfig/fonts.conf）如下：

xml<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
    <match>
        <test name="family"><string>serif</string></test>
        <edit name="family" mode="assign" binding="strong">
            <string>DejaVu Serif</string>
        </edit>
    </match>
    <match>
        <test name="family"><string>sans-serif</string></test>
        <edit name="family" mode="assign" binding="strong">
            <string>DejaVu Sans</string>
        </edit>
    </match>
    <match>
        <test name="family"><string>monospace</string></test>
        <edit name="family" mode="assign" binding="strong">
            <string>DejaVu Mono</string>
        </edit>
    </match>
    <match>
        <test name="family"><string>Arial</string></test>
        <edit name="family" mode="assign" binding="strong">
            <string>Liberation Sans</string>
        </edit>
    </match>
    <!-- ... -->
</fontconfig>

fc-match命令显示，sans和serif字体设置均正确（使用上述配置前输出为文泉驿字体）。

$ fc-match serif
DejaVuSerif.ttf: "DejaVu Serif" "Book"
$ fc-match sans
DejaVuSans.ttf: "DejaVu Sans" "Book"
$ fc-match monospace
odokai.ttf: "文鼎ＰＬ新中楷" "Regular"

我设置了monospace为DejaVu Mono，为什么实际上是其他字体？