Builds of libopenshot-audio for m68k (admittedly not a release
architecture) have been failing:

  ./../../modules/juce_core/text/juce_String.cpp: In member function 'void juce::StringHolder::compileTimeChecks()':
  ./../../modules/juce_core/system/juce_PlatformDefs.h:179:38: error: static assertion failed: sizeof (EmptyString) == sizeof (StringHolder)

Atomic<> evidently imposes a size overhead here. :-/

Could you please take a look?

Incidentally, you really ought to look into building against separately
packaged juce per Policy 4.13, but it also FTBFS on m68k (and on
non-Linux, as in #876792), so that wouldn't actually help here.

Thanks!