With the upgrade of devel/qscintilla2 to 2.10 it now depends on std::regex, which is only available since c++11. This breaks builds with gcc, so "compiler:c++11-lib" needs to be added to the USES list (untested thus far, will verify once my current poudriere bulk build completes).
Verified, USES= compiler:c++11-lib makes it build.
A commit references this bug:
Date: Fri Mar 9 16:53:38 UTC 2018
New revision: 463975
Fix build of devel/qscintilla2 on gcc platforms.
Submitted by: jhibbits
Thanks for the fix!
Thanks for the report :)