Comment # 1 on bug 1025863 from Michal Srb

The clang${version} package in Tumbleweed depends on libclang${version} which
in turn depends on libstdc++-devel, which depends on the package with system's
c++ library files. So since Tumbleweed it is guaranteed that some version of
libstdc++ library will be installed.

However, it is still possible to have newer gcc installed and not have the
matching libstdc++ installed. Clang will then autoselect the newest one and
fail the way described in this bug.

To fix that, we should build clang with -DGCC_INSTALL_PREFIX pointing to the
system gcc installation.