On Tue, Mar 02, 2021 at 09:53:41AM +0100, Jan Beulich wrote: > On 02.03.2021 09:14, Roger Pau Monné wrote: > > On Mon, Mar 01, 2021 at 06:01:36PM +0000, Andrew Cooper wrote: > >> On 01/03/2021 17:59, Andrew Cooper wrote: > >>> On 01/03/2021 09:58, Roger Pau Monne wrote: > >>>> clang++ relies on the C++ headers installed by g++, or else a clang > >>>> build will hit the following error: > >>>> > >>>> <built-in>:3:10: fatal error: 'cstring' file not found > >>>> #include "cstring" > >>>> ^~~~~~~~~ > >>>> 1 error generated. > >>>> make[10]: *** [Makefile:120: headers++.chk] Error 1 > >>>> > >>>> Reported-by: Stefano Stabellini <[email protected]> > >>>> Signed-off-by: Roger Pau Monné <[email protected]> > >>>> --- > >>>> Cc: Ian Jackson <[email protected]> > >>>> No real risk here from a release PoV, it's just pulling a package > >>>> required for the Alpine clang build. Worse that cold happen is that > >>>> the Alpine clang build broke, but it's already broken. > >>> Shouldn't this be fixed upstream in Alpine? Its clearly a packaging bug. > >> > >> Or (thinking about it), we've got a build system bug using g++ when it > >> should be using clang++. > > > > No, the check is using clang++, the issue is that clang++ doesn't > > install the standard c++ headers, and thus trying to use them (cstring > > in this case) fails. Installing the g++ package solves the issue > > because it installs the headers. > > I have to admit that I consider this odd. The g++ package should > neither provide nor depend on the headers. It may recommend their > installation. On my distro (SLES) the headers come from the > libstdc++-devel package, as I would have expected. There > additionally is a dependency of libclang5 (no -devel suffix!) on > libstdc++-devel (I suppose this is an indication that things > aren't quite right here either; I haven't checked an up-to-date > version of the distro yet, though).
Yes, that was indeed my first attempt as I've tried to install libstdc++, but there's no -devel counterpart for the package, and it only installs the libraries but not the headers. Then if I list the contents of the g++ package, I do see: ... usr/include/c++/10.2.1/cstring ... And clang++'s include path is: #include <...> search starts here: /usr/bin/../lib/gcc/x86_64-alpine-linux-musl/10.2.1/../../../../include/c++/10.2.1 /usr/bin/../lib/gcc/x86_64-alpine-linux-musl/10.2.1/../../../../include/c++/10.2.1/x86_64-alpine-linux-musl /usr/bin/../lib/gcc/x86_64-alpine-linux-musl/10.2.1/../../../../include/c++/10.2.1/backward /usr/include /usr/lib/clang/10.0.1/include So it does seem clang depends on the gcc c++ headers, I assume this is done in order to avoid having a duplicate set of c++ headers for clang and gcc? I really have no idea, but I do think clang package should depend on g++. Thanks, Roger.
