Recently dev-haskell/glib was patched for a similar error. I suspect that the other packages mentioned in Bug 727222 will also be impacted.
Created attachment 654666 [details] dev-haskell/gio-0.13.6.0 build log
Please check if this commit (0.13.8.1) fixes it: https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=a7a7d7b24aad01e2f809c3e10ec1f650a0e25ab1
It appears that ebuild made it into the tree before I could test. Works here.