Remove the --comp option in appimagetool

[pkwong4321]

I'm trying to build an appimage with xz compression due to AppImageLauncher not supporting zstd.
If i run appimagetool-x86_64.AppImage --comp xz .... , it will say "mksquashfs: Compressor "xz" is not supported!"
I believe it's becuase the bundled mksquashfs did not enable any compression methods other than zstd, making --comp meaningless
ref: ci/install-static-mksquashfs.sh
make -j"$jobs" GZIP_SUPPORT=0 XZ_SUPPORT=0 LZO_SUPPORT=0 LZ4_SUPPORT=0 ZSTD_SUPPORT=1 COMP_DEFAULT=zstd LDFLAGS=-static USE_PREBUILT_MANPAGES=y install

[probonopd]

Hi @pkwong4321, thanks for your comment. However, we are standardizing (no pun intended) on zstd.

• Release versions/v1.0.md AppImageSpec#34

So if you need AppImageLauncher, it might be a good idea to ask its developers to support zstd.

[pkwong4321]

Just want to say the binary distributed here does not work with anything other than zstd, specified or not. If you want to standardize with zstd, you might want to remove the --comp option in appimagetool?

[probonopd]

Yes, good idea. Thanks!

[Samueru-sama]

Note that removing the --comp option will break workflows that are already using --comp zstd.

[probonopd]

Good point...

[TheAssassin]

We may want to deprecate the option (i.e., render it useless) and mention its deprecation. Alternatively, we may just keep it. Who knows what compression schemes will be used in the future.