Upstream issue is <https://github.com/anholt/libepoxy/issues/106> "gl prototypes aren't surrounded by extern "C" and so fail to link to c++ code", but the fix <https://github.com/anholt/libepoxy/commit/7d58fd3d47d2d69f2b1b9f08325302e4eeff9ebe> "Merge pull request #107 from anholt/issue-106: Add C++ guards around generated headers" is only on master, not on 1.4.1, so is missing from libepoxy-devel-1.4.1-1.fc25. Would be great if that fix could be backported to F25. (We noticed when doing development builds of LibreOffice, which has a Clang plugin to emit additional warnings about the code. That plugin suppresses some false positives based on whether extern "C" functions are involved, and so started to fail and emit false positive warnings now.)
libepoxy-1.4.3-1.fc25 has been submitted as an update to Fedora 25. https://bodhi.fedoraproject.org/updates/FEDORA-2017-842bdbd2da
libepoxy-1.4.3-1.fc25 has been pushed to the Fedora 25 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2017-842bdbd2da
libepoxy-1.4.3-1.fc25 has been pushed to the Fedora 25 stable repository. If problems still persist, please make note of it in this bug report.