Provide a way to display make's compilation steps for native exts

[luke-gruber]

The problem

I searched for similar problems, sorry if this has been filed already.

Running bundle install --verbose doesn't show the compiler invocation commands for native extensions. I want to be able to see these compiler commands sometimes because I had a build in CI that was taking 20 minutes to install a gem with native extensions, and I didn't know why it was happening. I didn't even know which gem was causing the issue, because gems were being downloaded in parallel and the last output was:

installing gem "some_gem"
However, it was stuck compiling a different gem, further back in the output.

Things I tried

I tried V=1 bundle install as well but it didn't work. If you do make V=1 it normally gives lots of output. I could be doing something wrong though.

The solution

I'm not sure what's a better solution: add a configurable option to bundler or allow certain ENV vars through to the make subprocess.

[luke-gruber]

I just figured out it works if you put :verbose: 1 in your ~/.gemrc, but I had to read the source to get that info. It would be nice if this was documented somewhere, or maybe it is but I couldn't find it.

[indirect]

I think it probably makes sense to turn on gem install's verbose output while running bundle install --verbose, but yes, you have discovered the troubleshooting steps, which are to run gem install <NAME> --verbose for each gem you need to troubleshoot. Bundler doesn't offer a way to install a single gem, so it's expected that troubleshooting will involve using gem install.

[luke-gruber]

Sometimes the environment that you're in (like CI) is running bundle install, and it's going through a quite complicated build pipeline that you can't simply SSH into and try gem install some_gem --verbose in the container. Also, it's not possible to know which gem is taking so long without verbose output from the compiler because the output that bundler gives is interleaved with other gem installation output as it runs jobs in parallel. The last line that gets blocked on is not necessarily the problematic gem. I was running bundle install locally and all gems were built relatively fast, but one gem was taking 20 minutes to compile in the container because it was missing all sorts of dependencies that were getting auto installed, and I want to have a way to get that info.