The error shown when the compiler fails to build a module from its
textual interface has been creating some confusion. This is a proposal
to make it more useful to the programmer not working in the SDK, insist
on looking at the previous errors first, put less emphasis on possible
compiler bugs, and always show alternatives to the incompatible
compilers issue as this is the most common case now.
The driver can now schedule jobs which typecheck just-emitted module interfaces to ensure that they can be consumed later. This can be enabled manually by passing `-verify-emitted-module-interface` to the driver.