I’ve just tried to reproduce this, and I can’t - regina-normal seems to be building fine under current sid/amd64 with gcc-5 and g++-5 installed and the relevant CC / CXX environment variables set. The build log confirms that gcc-5 and g++-5 are indeed being called during the build.
I’d be happy if you could do another test rebuild to see if it’s still broken at your end, or if the problem has sorted itself out since the bug was filed back in February. Thanks - Ben. -- To UNSUBSCRIBE, email to debian-bugs-rc-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org