Browser Development • 34.2.0 build failed, --enable-jxl unknown ??

Last time I built PM 34.1.0 with the very same .mozconfig and it went through just fine, build succeeded. When trying to build 34.2.0 it failed with Unknown option: --enable-jxl. When was this option removed, and why? What are the implications?

Relevant part of the build log:

CODE:

 0:10.16 Traceback (most recent call last): 0:10.16 File "/media/dragos/AllData2/Programming/Linux/Sources+scripts/PaleMoon/palemoon2026/configure.py", line 32, in <module> 0:10.16 sys.exit(main(sys.argv)) 0:10.16 File "/media/dragos/AllData2/Programming/Linux/Sources+scripts/PaleMoon/palemoon2026/configure.py", line 24, in main 0:10.16 sandbox.run(os.path.join(os.path.dirname(__file__), 'moz.configure')) 0:10.16 File "/media/dragos/AllData2/Programming/Linux/Sources+scripts/PaleMoon/palemoon2026/platform/python/mozbuild/mozbuild/configure/__init__.py", line 360, in run 0:10.16 raise InvalidOptionError('Unknown option: %s' % without_value) 0:10.16 mozbuild.configure.options.InvalidOptionError: Unknown option: --enable-jxl 0:10.20 *** Fix above errors and then restart with\ 0:10.20 "/usr/bin/make -f client.mk build" 0:10.21 make: *** [client.mk:370: configure] Error 1

On a related note - maybe the new Python3 build environment would try to catch such exceptions graciously and provide the user with a choice to continue with the offending option disabled, or stop the build, fix the configuration, and rebuild. This considering there may be more than one offending option, and restarting the build process N times just to find yet another bad option might be at least annoying and time wasting.