Hello,
I've been investigating this issue on Ubuntu and I believe I've found
the solution.
The "webrtcbin" element is provided by the package
"gstreamer1.0-plugins-bad", which is not a runtime dependency of
libervia-backend (only gir1.2-gst-plugins-bad-1.0 is in the list).
Adding it as dependency causes the test to fail at another location with
the error:
gi.repository.GLib.GError: gst_parse_error: could not link rtpvp8pay0 to
sendrecv, sendrecv can't handle caps application/x-rtp,
media=(string)video, encoding-name=(string)VP8, payload=(int)97 (3)
After some research I've found that "gstreamer1.0-nice" is also required.
So adding "gstreamer1.0-plugins-bad" and "gstreamer1.0-nice" as runtime
dependencies resolves the issue.
Here is the PPA with these changes I used to test it:
https://launchpad.net/~danilogondolfo/+archive/ubuntu/libervia-backend/+packages
And here is the autopkgtest results:
https://autopkgtest.ubuntu.com/results/autopkgtest-oracular-danilogondolfo-libervia-backend/oracular/amd64/libe/libervia-backend/20240827_124603_b880c@/log.gz
