If we need to use "fc-cache -f", suggest add it to document.

At 2017-01-14 05:23:55, "Danny Milosavljevic" <dannym@scratchpost.org> wrote:
>Hi,
>
>On Fri, 13 Jan 2017 23:16:53 +0800 (CST)
>tumashu  <tumashu@163.com> wrote:
>
>> When I install a font with a non-root account,  the font just can't be found by "fc-list",
>> and run "fc-cache" is useless too, But run "fc-cache -f" can cache the installed font,
>> it it a bug or just my machine problom?
>
>I don't know, sorry. It may be that fc-cache uses timestamps (mtime) to figure out whether a directory changed or not and that won't work for us since we always use the same mtime (for reproducibility). But that's just a guess - I hope someone else knows it...
>