https://github.com/ruby/rubygems/commit/9b169c700f

DSLError prints the specific line in a Gemfile where the error was
raised. That's helpful when the error was explicitly raised by the
Gemfile DSL or, in the case it's implicitly raised, when the offending
code lives right in the Gemfile.

If it's an internal error, or something buried dowm in user code called
from the Gemfile, `DSLError` is not helpful since it hides the actual
culprit.

This commit tries to only raise `DSLError` in the cases mentioned above
and otherwise let the original error be raised.

https://github.com/rubygems/rubygems/commit/b30ff5a682

https://github.com/rubygems/rubygems/commit/70243b1d72

https://github.com/rubygems/rubygems/commit/4c1a0511b6

https://github.com/rubygems/rubygems/commit/d768be0c65

  from https://github.com/rubygems/rubygems/commit/72fd3dd2096af16d797ad0cd8e0d2a8869e240b3

Since we're at it. This generates a bunch of warnings and seems like a
brittle way to test things, so let's get rid of it.

https://github.com/rubygems/rubygems/commit/f5d45520e0