macOS: linker error (starting in ffmpeg) with Xcode 15

[jhoyt4]

With the introduction to Xcode 15, Apple has moved to a new linker and introduced the "-ld_classic" linker flag as a work around. Without this flag, FFMPEG fails to compile on systems with Xcode 15 (i.e. Sonoma) and possibly beyond.

I've successfully tested a fix at compile time by adding this line to the compile script (or manually in the shell)
export LDFLAGS="$LDFLAGS -Wl,-ld_classic"

• Platform: macOS 14.0 (Sonoma) with Xcode 15 (arm64 and X86_64)

• MythTV version: fixes/33 and master

• Package version:

• Component:ffmpeg

What steps will reproduce the bug?

Attempt to compile MythTV either manually or with the "compileMythfrontendAnsible.zsh" script in packaging.

How often does it reproduce? Is there a required condition?

Every time with Xcode 15

What is the expected behaviour?

Successful compilation.

What do you see instead?

Logs from v33 and master attached. X86_64 shows similar errors.

Additional information

See related FFMPEG bug report and proposed fix from the Spack community for proposed bandaid.

v33 ARM.txt
master ARM.txt

[jhoyt4]

I'm looking for a suggestion on where to add the "-ld_classic" linker flag so that it only gets fed to FFMPEG to see if that is the only component broken with the new linker.

[linuxdude42]

Try adding "add_ldflags -ld_classic" somewhere in mythtv/external/FFmpeg/configure before the line that reads "cat > ffbuild/config.mak <<EOF".

[linuxdude42]

Looks like I need a new mac mini. I can't upgrade past Monterey.

[jhoyt4]

Have you considered running OpenCore to patch your current system to run more a recent version?

[jhoyt4]

Try adding "add_ldflags -ld_classic" somewhere in mythtv/external/FFmpeg/configure before the line that reads "cat > ffbuild/config.mak <<EOF".

Thanks! I added "test ${clang_version%%.*} -ge 15 && add_ldflags -ld_classic" to line 5550 (in the darwin clang section). It's gotten past the FFMPEG issue and successfully compiled. Trying again with mythplugins. If all goes well, I'll work up a PR.