fontconfig-2.10.92 is marked stable and it has:
but the latest stable version of freetype (2.4.11) does not support multilib. please mark a newer one stable or backport the multilib logic to 2.4.x.
*** Bug 506306 has been marked as a duplicate of this bug. ***
*** This bug has been marked as a duplicate of bug 506298 ***
this is not a duplicate. fontconfig/freetype specifically is broken.
No, it's not. The stable version depends only on the flags that are implicitly added by use.force which works fine.
i think what you mean to say is that the multilib project does not currently support stable at all and masks out the flags via package.use.stable.mask
hopefully newer freetype will be stabilized soon for an unrelated reason