Update: The hotfix is now available for download.
I’ve just tracked down the cause for a crash on some macOS systems which is related to the opus audio codec.
This bug affects all macOS systems that use CPUs that do not support AVX. AVX was introduced in 2011, so all mac systems from before 2011 will not currently work because of this issue. Mac systems from after 2011 that use an older CPU (such as the 2012 MacPro hex-core) also will not work.
The crash will be characterised by X-Plane crashing when a connection is made, or the audio setup dialogue being displayed. The macOS crashlog will indicate “Exception Type: EXC_BAD_INSTRUCTION (SIGILL)
” with the crashed thread crashing in mac.xpl
at silk_VAD_Init + 4
Unfortunately, the opus team accidentally force-enabled AVX optimisations in their build tooling for opus, and so if the library is built on any AVX-capable mac, the result uses AVX, irrespective as to any options we set to inhibit that support.
I’ve patched the XSquawkBox libopus to disable this and as long as this doesn’t break the Linux build (the same options get used there), this update will be published as hotfix 2.
If you are using an old Mac – please hold off further bug reports until beta 4 hotfix 2 is published.