Closed markaylett closed 5 years ago
The build issue is caused by a bug in GCC: https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=271083
The following patch can be applied to the std::variant
as a work-around:
PR-libstdc-90397-fix-std-variant-friend-declarations.diff.txt
@rfernandes reported an issue with the std/variant header in GCC 9.1.0 that breaks the build.