I ported my opensource archiver (C++) to Mac, successfully compiling with clang++ on Intel and PowerPC machines
https://github.com/fcorbelli/zpaqfranz
In theory (I'm working on it) it should allow the creation of backups immune to ransomware (on systems with chflags sappend, such as the various BSDs and - perhaps - Macs).
However, I do not have one of the brand new Mac M1/M2 available to verify its correct functioning (it is necessary to use software emulation instead of the integrated JIT compiler for amd64/i386 SSE2 for non-Intel CPUs)
If anyone is interested I would be very happy to compiling the very last unreleased build, this one
https://github.com/fcorbelli/zpaqfranz/blob/macos_mx/zpaqfranz.cpp
with something like
g++ -Dunix -O3 -DNOJIT zpaqfranz.cpp -o zpaqfranz -pthread -std=c++11
then a
./zpaqfranz autotest -all
for the quick-and-dirty test (there is a long autotest too)
I will greatly appreciate any help
Franco Corbelli