Extended Description

https://treeherder.mozilla.org/logviewer?job_id=330246994&repo=try&lineNumber=59045

When linking rust code compiled with coverage enabled, we see error: duplicate symbol: __gcov_dump and similar.

Bisection points to 8f91f38 https://reviews.llvm.org/D86142 which is odd because at first glance I wouldn't think that patch should affect non-fortran.

Should those gcov symbols have been considered mergeable?

Our build setup is pretty complex and I'm still trying to understand the failure better, but I wanted to report this as early as possible given the 12.0.0 timeline. Right now I only have the CI logs but I'll try reproducing it locally. If there are any specific pieces of information that I should try to extract to help people debug this, please let me know.