I've got this while reproducing lp:1625846 (and running on mesa-drm, not on X11 and Mir-0.24, not a locally built trunk).
Although the stack traces are a bit different: all of the threads are in __lll_lock_wait(), pthread_cond_wait() __GI___pthread_mutex_lock(), or poll().
I'm also lacking Mir debug symbols, so I'm not sure how useful this is.
I've got this while reproducing lp:1625846 (and running on mesa-drm, not on X11 and Mir-0.24, not a locally built trunk).
Although the stack traces are a bit different: all of the threads are in __lll_lock_wait(), pthread_cond_wait() __GI___ pthread_ mutex_lock( ), or poll().
I'm also lacking Mir debug symbols, so I'm not sure how useful this is.