Add --debug flag

[NickLaMuro]

Was going to use this to "--debug" some issues wih the ManageIQ/manageiq Rails 6.0 effort (specifically some failing builds due in manageiq-ui-classic), but turns out I was able figure it out without this change.

Regardless, I could see this being useful for others, so here is a PR.

🍅 🍅 🍅

[kbrock]

@Fryguy do you want this? I could rebase if you do

[Fryguy]

Up to @agrare but let's get through the github actions first

[agrare]

We print out overrides already: https://github.com/ManageIQ/manageiq-cross_repo-tests/runs/5289161095?check_suite_focus=true#step:6:71 so not sure how much extra this adds?

[NickLaMuro]

Got pinged on this, so figured I would chime in, but have no hard feelings for what decision is made:

(also, hey everyone! 👋 )

Regarding the puts "Contents of #{override_path}" part of this change, I find that to be the least useful part of the change, as it was just something that worked for me. I believe (memory failing me) it was mostly a double check that what was being generated by cross repo was what I expected, but I agree with @agrare that it probably already exists to some extent via bundler-inject.

I think the real value of the --debug flag is that it is available to the end user when doing --help, instead of having to know the ENV var exists by looking at the codebase (currently not in the README.md either)

Anyway, my </2cents>. ✌️

[agrare]

👋 hey @NickLaMuro