This is an auto-filled bug because dev-libs/protobuf calls cc directly. The issue was originally discovered on x86, but it may be reproducible on other arches as well. Attached build log and emerge --info. NOTE: To reproduce this issue you may want to temporarily move the /usr/bin/cc - /usr/bin/gcc binaries.
Created attachment 634092 [details] build.log build log and emerge --info
AC_PROG_CC and AC_PROG_CXX use ${CC} and ${CXX}, but AX_PROG_CC_FOR_BUILD (alias: AC_PROG_CC_FOR_BUILD) and AX_PROG_CXX_FOR_BUILD (alias: AC_PROG_CXX_FOR_BUILD) use ${CC_FOR_BUILD} and ${CXX_FOR_BUILD} (and ${CPP_FOR_BUILD}, ${CXXCPP_FOR_BUILD}, ${CPPFLAGS_FOR_BUILD}, ${CXXCPPFLAGS_FOR_BUILD}, ${CFLAGS_FOR_BUILD}, ${CXXFLAGS_FOR_BUILD}, ${LDFLAGS_FOR_BUILD}). https://github.com/protocolbuffers/protobuf/blob/c74057267d64d0b5b8a48feeab2d5b015590aca0/configure.ac#L76-L78 https://www.gnu.org/software/autoconf-archive/ax_prog_cc_for_build.html https://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=blob;f=m4/ax_prog_cc_for_build.m4 https://www.gnu.org/software/autoconf-archive/ax_prog_cxx_for_build.html https://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=blob;f=m4/ax_prog_cxx_for_build.m4
https://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=commit;h=9c26407efb0322dda2c08fada6a67dde1c690e74 added automatic detection of compiler based on --build=${CBUILD}. This works for native ABI, but not for non-native ABI: (On multilib x86_64 system) ・ `configure --build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu` finds `x86_64-pc-linux-gnu-gcc`. ・ `CC="x86_64-pc-linux-gnu-gcc -m32" configure --build=i686-pc-linux-gnu --host=i686-pc-linux-gnu` searches for non-existent `i686-pc-linux-gnu-gcc` and fails, instead of searching for `x86_64-pc-linux-gnu-gcc -m32`.
*_FOR_BUILD variables are no longer used by build system in >=dev-libs/protobuf-3.6.1: https://github.com/protocolbuffers/protobuf/issues/7413
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=60b7072a739ba280d075d6d91da644cd6f3ee372 commit 60b7072a739ba280d075d6d91da644cd6f3ee372 Author: Arfrever Frehtes Taifersar Arahesis <Arfrever@Apache.Org> AuthorDate: 2020-06-13 18:26:41 +0000 Commit: Mike Gilbert <floppym@gentoo.org> CommitDate: 2020-06-13 18:59:13 +0000 dev-libs/protobuf: Use not AC_PROG_CXX_FOR_BUILD. Closes: https://bugs.gentoo.org/718876 Signed-off-by: Arfrever Frehtes Taifersar Arahesis <Arfrever@Apache.Org> Signed-off-by: Mike Gilbert <floppym@gentoo.org> dev-libs/protobuf/protobuf-3.10.1.ebuild | 4 ++++ dev-libs/protobuf/protobuf-3.11.4.ebuild | 4 ++++ 2 files changed, 8 insertions(+)