[service] Installer packages can't be used in older enviroments

[Croydon]

For some reason installers build by CCI seems to use the new CXX11 ABI which then doesn't run in GCC 4.9 containers. Am I missing something here or is this effectively a bug? 🤔

https://travis-ci.com/bincrafters/conan-sdl2/jobs/247592499#L1801

// @ericLemanissier @SSE4

[Croydon]

Discussion started here: #125 (comment)

[ericLemanissier]

another occurrence of this problem: https://travis-ci.com/bincrafters/conan-xkbcommon/jobs/258981515#L1062
This happens probably because ninja recipe deletes self.info.settings.compiler. Maybe it it could be fixed by deleting all subkeys of self.settings.compiler except libcxx ?

[danimtb]

I believe that's not going to solve the problem, as compiler.libcxx does not model glibc but the C++ standard library

[ericLemanissier]

the missing symbol is _ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE7reserveEm which is demangled as std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::reserve(unsigned long) so it definitely looks like a c++ standard library issue to me. Platforms with gcc 4.9 cannot have C++11 version of the abi, because it was introduced in gcc 5.1

[uilianries]

The installer packages should use the centos6 docker image... We need to check it.

[uilianries]

I can't access ninja installer CI log, it's so old. Anyway, I think we are using conanio/gcc5

[ericLemanissier]

another possibility is to compile ninja with -static-libstdc++ so that it does not depend on dynamic libraries at all. Would such a change be accepted ? Other installer packages using std library would still have the problem.

[SSE4]

unfortunately, -static-libstdc++ isn't enough :( still, glibc problem arises after that, which is not that easy to deal.

[ericLemanissier]

so all installer packages should be built on the platform with oldest glibc right ? so CCI should use gcc4.9 image for these ?

[SSE4]

yeah, I believe so, it's the most simple solution. however, CCI doesn't have a concept of installer packages, and there is no way to specify such information that package must be built in a special way.

[SSE4]

@danimtb @uilianries we need to definitely make some action on this, as it blocks several recipes (e.g. fribidi).

[Croydon]

If the CI system would be open sourced... 😉

Random wild guess: Maybe GCC 5 is the first compiler the CI compiles for and therefore uses it for installer packages? Maybe it would be enough to put GCC 4.9 first?

[danimtb]

With the changes introduced in the latest deployment https://github.com/conan-io/conan-center-index/blob/master/docs/changelog.md#17-september-2020---1742-cest, the "installer" packages should be built now using the oldest gcc version in Linux (gcc 4.9 in our case), thus using the oldest glibc version possible right now.

• This should unblock issues related to executables not running in CI for libraries that use those "installers" as build requires.
• This should remove the need of adding the compiler setting for those "installer" recipes just to force them to build with gcc 4.9 to avoid this issue.

We hope this unblocks some of the PRs hit by this issue and we will continue working to improve the situation around it. Thank you!

[danimtb]

I'd consider this issue closed with the documentation in #3328