fix: install.sh was calling systemctl on Darwin

[jancona]

In attempting to upgrade to 0.17.2 on MacOS, I noticed errors when running install.sh. It appears that the changes in be09303 broke the Darwin install. I restore the install_unix() function, which had be renamed, to contain the common code, and left the Linux-specific code in install_or_update_unix().

I haven't tested on Linux, but the change is small enough that I think I haven't broken anything.

[garethgeorge]

Ah, thanks for catching this! LGTM.

I'll also call out, incase it's convenient to you, there's now a brew tap for backrest https://github.com/garethgeorge/homebrew-backrest-tap which is hopefully a more robust way of keeping it up to date. I plan to support both this and the script install. Thanks for the fix!

[jancona]

Thanks. I actually noticed the Homebrew option right about when I finished fixing the install script. I switch to Homebrew right after I finished the PR.

[garethgeorge]

Hi, I'm evaluating relicensing Backrest as AGPL-3.0 . Thanks for contributing this fix!

I'm wondering if you'd be willing to retroactively sign a CLA? Or grant more specific permission to retain the copyright for your PRs but relicense your changes in the codebase under AGPL-3.0 .

I've become aware of a few SAAS looking at selling Backrest which goes philosophically against what I created it for (well they're welcome to -- but their platforms should be OSS and self-hostable re: the same freedoms Backrest provides!).