Improve dependencies check against :control_branch

[ananace]

With this, ra10ke will no longer generate false positives and excessive log spam on versions of the R10k gem >= 3.10.0

It also improves performance and removes unnecessary load by completely skipping version checks for modules using control branch, since that will always be a no-op anyway, and the check would cause each repo to be pulled twice just to do said no-op. (First by R10k's cache verifying that the branch exists, then followed by ra10ke's Git.ls_remote call to check that it really is a branch)

As it turns out, the threaded checking caused git to run into the subshell limit on our r10k repo if the repository host was slow to respond.

[bastelfreak]

Thanks for the PR! What kind of false positives did you get? And which errors? Is that something we should document in the changelog?

[ananace]

$ bundle exec rake r10k:dependencies |& tee error.log
...
$ wc -l error.log
1647 error.log

We're running this in CI, so the false positive is mainly that the check errors out completely if there's a :control_branch module, as r10k will now refuse to validate its ref.
It helpfully throws a warning message in the log for each such module, before then also generating an error for each of the threads.

E.g.

vendor/ruby/3.2.0/gems/r10k-5.0.0/lib/r10k/module/git.rb:167:in `validate_ref': Unable to manage Puppetfile content 'aaa_clients': Could not resolve control repo branch and no default provided. r10k no longer hardcodes 'master' as the default ref. Consider setting a ref per module in the Puppetfile or setting git:default_ref in your r10k config. (ArgumentError)

Setting an actual R10K::Environment object was enough to get past that error/warning spam, but then we ran into the threading issue - which was causing EPIPE errors as git was failing to spin up porcelain subshells for all our 328 control_branch modules.

 

Not sure exactly what to put in the changelog though, it's a general performance improvement if you're using control_branch, but also an error fix for r10k gem versions 3.10.0 and newer.

[bastelfreak]

I raised #117 to have the bugfix in the changelog