Bug#998108: Tracking this bug down

[Eugen Dedu]

Maybe I am wrong, but, for me, the simplest method to track this bug 
down is to check the changes between the two versions, 93.0 and 
93.0-1+b1.  Firefox code has not changed, only one or some libraries it 
depends on.  I thought that the only change is in libvpx version, but, 
surprisingly, a previous comment mentions that rebuilding firefox with 
old vpx (libvpx6) still exhibits the bug.  I think that libc6 is out of 
question, because the last package is 19 Sep, too old wrt this bug; the 
same for gcc-11, the last package being on 21 Oct.  Doesn't this 
(checking the changes) sound like a good approach to find the cause of 
the problem?