Correction, only when the ffmpeg config is extended with:

ffmpeg_%.bbappend:1:PACKAGECONFIG:append = " x264"

This appears to be because ffmpeg and x264 actually have a circular dependency on each other, and not specific to SPDX. ffmpeg.bb has:

PACKAGECONFIG[x264] = "--enable-libx264,--disable-libx264,x264"

while x264.bb has:

PACKAGECONFIG[ffmpeg] = "--enable-lavf --enable-swscale,--disable-lavf --disable-swscale,ffmpeg"


Thus, if "x264" is enabled in ffmpeg and "ffmpeg" is enabled in x264, they have a circular build time dependency.

I'm not sure how to break this other than add a comment in each recipe that indicates this is the case (or some sort of ffmpeg-minimal shenanigans). I will add a comment at least.

Regardless, it's not an SPDX problem

Yes, I also came to the same conclusion. It seems like x264 doesn't need the whole ffmpeg, but only a few libraries from there. If we split them in a subpackage, would that work for DEPENDS? But I doubt it, IIRC it works on a recipe level, not on a package level, right?

Correct; since it's a build time dependency loop, it occurs before packaging is even known (in fact, circular runtime dependencies are allowed).

The solution is _probably_ some sort of "minimal" or "initial" ffmpeg build that doesn't produce packages and that x264 can depend on at build time, but then it's runtime dependencies are on the "full" ffmepg; making sure the two versions of ffmpeg are built the same (such that they are interchangeable at runtime) is the tricky part of that.

Comment was added: https://git.openembedded.org/openembedded-core/commit/?id=757a032c5c7672ee66ec4984d34e1f03052936ad

I believe the underlying issue still has to be fixed.

Not sure how to fix the circular dependency. The comment lets the users know of the problem, but I won't have time to fix it "properly"