Report errors when generating indexes

[hubertp]

Pull Request Description

--compile command would run the compilation pipeline but silently omit any encountered errors, thus skipping the serialization. This maybe was a good idea in the past but it was problematic now that we generate indexes on build time.
This resulted in rather obscure errors (#6092) for modules that were missing their caches.

The change should significantly improve developers' experience when working on stdlib.

Important Notes

Making compilation more resilient to sudden cache misses is a separate item to be worked on.

Checklist

Please ensure that the following checklist has been satisfied before submitting the PR:

• The documentation has been updated, if necessary.
• Screenshots/screencasts have been attached, if there are any visual changes. For interactive or animated visual changes, a screencast is preferred.
• All code follows the
  Scala,
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  and
  Rust
  style guides. In case you are using a language not listed above, follow the Rust style guide.
• All code has been tested:
  • Unit tests have been written where possible.
  • If GUI codebase was changed, the GUI was tested when built using ./run ide build.

[radeusgd]

Thanks for the fix! This will make our lives much easier.

I'm wondering if we could add one more layer of safety - when loading the IR cache, can we check if the loaded IR contains any errors and reject such a cache as 'invalid', to force a recompilation? Then, even if somehow a cache with errors becomes generated, our compiler will try its best to recompile to see if the errors go away - and if not - it will at least display good errors.

[hubertp]

Thanks for the fix! This will make our lives much easier.

I'm wondering if we could add one more layer of safety - when loading the IR cache, can we check if the loaded IR contains any errors and reject such a cache as 'invalid', to force a recompilation? Then, even if somehow a cache with errors becomes generated, our compiler will try its best to recompile to see if the errors go away - and if not - it will at least display good errors.

It's part of the follow up work.