Previously, the GCC version check functions from toolchain-funcs.eclass would return the active GCC version, even if CC was overridden (eg. with clang). This behaviour was changed so that the active compiler is queried, causing these checks to fail with clang since it reports itself as GCC 4.2. From $URL: The common use cases: a. checking for a specific gcc version: [[ $(gcc-major-version) = 5 && $(gcc-minor-version) -le 2 ]] would become: tc-is-gcc && [[ $(gcc-major-version) = 5 && $(gcc-minor-version) -le 2 ]] i.e. it would not trigger for clang. b. applying clang-specific quirks (discouraged but people still do that): [[ ${CC} == *clang* ]] && ... would become: tc-is-clang && ...
