There is a build error when building LibWebRTC (-DUSE_GSTREAMER_WEBRTC=FALSE). The header LibWebRTCVPXVideoDecoder.h is included which at the same time also includes WebKitDecoder.h which includes Availability.h. The latter header is Mac specific.
Pull request: https://github.com/webkit/webkit/pull/8967
Committed 259221@main (676291717bcd): <https://commits.webkit.org/259221@main> Reviewed commits have been landed. Closing PR #8967 and removing active labels.
<rdar://problem/104563527>
*** Bug 251019 has been marked as a duplicate of this bug. ***