Sometimes our custom errors wrap an underlying error and try to show the wrapped error and backtrace. See for example https://github.com/rubygems/rubygems/blob/c63c4b0305de7a5712436d37decca648b14b0091/bundler/lib/bundler/errors.rb#L134-L148.

@segiddins suggested that we may be able to use Exception#detailed_message to show the cause instead. I noticed that it's only available in newer rubies, but we could gradually move to that if it simplifies things. I also noticed there's Exception#full_message that includes the backtrace.

We should evaluate whether this makes sense for us and will simplify our errors, or whether we should not bother.