if you read the PR comments you will see why it hasn't been merged, we had a couple of concerns... after all once its merged, users will expect (understandably) for it to be maintained and supported...
unfortunately, we didn't get any response from the original author.
I guess we have to now decide if to take the 'hit' now, and do the additional work required, the issue is , I don't have Arch Linux installed... so thats even more effort required to get it working!
please also bare in mind, there are lots of flavours of Linux, supporting all of them is just impossible.
note: you could of course go to authors repo, and pull this one file, if you want to just use it as is.
EDIT: final note... if you look at the build.sh, you will see all it does is get various packages and then build them, so for other variants of linux its not too difficult to do this manually.
once the packages are all built, the all the 'day to day' scripts of Axoloti should work with any flavour of unix. (assuming a reasonable sh implementation)