Comment 32 for bug 1325230

(In reply to comment #22)
> If this is a regression, then what change caused it?

Not really I'd say. the change for this workaround is mentioned above. if you want a certain link to the commit:
http://cgit.freedesktop.org/fontconfig/commit/?id=c6aa4d4bfcbed14f39d070fe7ef90a4b74642ee7

It is in 2.11.1 BTW.