I think it never worked, and the API docs do not mention it (only the single .issue property),
and either way this usage here does not seem helpful, issue/description still contains the same unfriendly text as in the exception message already
PSR-4 is much more robust and predictable. But to do this,
a source root dir must be specified for every module.
This could be done in the root file, but this is not very modular.
Instead, now every module declares its own source root by using
the amazing Composer Merge Plugin. This approach allows each module
to also declare its own dependencies. Together, these changes allow
modules to be easily extractable to separate pacakges when the need
arises, and in general improves modularity significantly.
