OK, I've re-tested with a hacked version of mesa.so.2 where the above leak is fixed and confirmed lp:~vanvugt/mir/fix-1527449 is indeed the fix for this bug.
Unfortunately it's only fixable for future Mir versions because we're not about to release patches for Mir 0.14 etc.
So if you do hit this bug in the mean time just use the workaround: Remove all old versions of the package "mir-client-platform-mesa*" from your system. In future when Mir 0.19 is the "old" version you have lingering on your machine along with newer versions, the bug won't exist any more.
OK, I've re-tested with a hacked version of mesa.so.2 where the above leak is fixed and confirmed lp:~vanvugt/mir/fix-1527449 is indeed the fix for this bug.
Unfortunately it's only fixable for future Mir versions because we're not about to release patches for Mir 0.14 etc.
So if you do hit this bug in the mean time just use the workaround: Remove all old versions of the package "mir-client- platform- mesa*" from your system. In future when Mir 0.19 is the "old" version you have lingering on your machine along with newer versions, the bug won't exist any more.