Gentoo's Bugzilla –
Attachment 447708 Details for
Bug 594994sci-biology/bedtools-2.20.1 : ../.../FileRecordTypeChecker.h:120:44: error: ‘constexpr’ needed for in-class initialization of static data member ‘const float FileRecordTypeChecker::PERCENTAGE_PRINTABLE’ of non-integral type [-fpermissive]