I am using genisoimage and the dmg util from hfsplus-tools on RH 9.3 to produce dmg files on Linux. Specifically, a common java program is jpackage on 2 different platforms (intel mac and newer apple silicon M2). Each output DMG is opened with hdiutil mount -nobrowse file.dmg and the tree of contents scp’d to Linux in separate architecture-specific directories. This allows us to create a Linux-based “template”. New versions of jar files can be compiled and dropped into the template directly on Linux and the DMG created independent of the Mac. The key differentiator in the two templates is the architecture-specific launcher program i.e.

11.10/arm64/MyApp.app/Contents/MacOS/MyApp: Mach-O 64-bit arm64 executable, flags:<NOUNDEFS|DYLDLINK|TWOLEVEL|WEAK_DEFINES|BINDS_TO_WEAK|PIE>
11.10/i386/MyApp.app/Contents/MacOS/MyApp: Mach-O 64-bit x86_64 executable, flags:<NOUNDEFS|DYLDLINK|TWOLEVEL|WEAK_DEFINES|BINDS_TO_WEAK|PIE>

The commands are:

genisoimage -V MyApp -D -R -apple -no-pad -o proto.img path_to_template
dmg dmg proto.img final.dmg

This works for the arm64 build in that final.dmg can be downloaded to an apple silicon mac and opened and the DMG behaves properly. On the x64 build however, downloading and launching final.dmg yields an error dialogue reading “The following disk images couldn’t be opened: final.dmg: invalid checksum”. What is puzzling is most of the genisoimage/dmg answers here on SO predate apple silicon so this must have worked in the past. Any clues?