Ucm exits with "No builtin type called: io2.Failure" when calling new IO functions

[rlmark]

When calling some of the new IO functions (I was experimenting with Sockets so the transcript contains that as an example) the following error will surface and the ucm will exit.

No builtin type called: io2.Failure
CallStack (from HasCallStack):
  error, called at src/Unison/Runtime/IOSource.hs:63:16 in unison-parser-typechecker-0.0.0-6U6boimwb8GAC5qrhLfs8h:Unison.Runtime.IOSource

Attached is a transcript which should replicate the issue
fix2027.md

[rlmark]

Also this transcript involves includes pulling all of the base library (🕐 ) but it's actually material for the error to surface.

[pchiusano]

@dolio I see what's going on - the runtime is referencing IOSource.failureReference (which should have been deleted as it doesn't exist in the Unison source included in IOSource) when it should be referencing Unison.Builtin.Decls.failureRef.

I'm guessing this is only triggered by I/O programs that actually throw errors (and maybe you even have to inspect the type of the error in a certain way to trigger it). I'd delete IOSource.failureReference and add a regression test to io.md transcript that doesn't require pulling all of base.

I'd also audit all the imports of stuff from IOSource in the runtime - most of those should be pointing to things in Unison.Builtin.Decls.

~/unison [trunk●] » rg failureReference 

parser-typechecker/src/Unison/Runtime/Builtin.hs
35:import Unison.Runtime.IOSource (ioFailureReference, tlsFailureReference, eitherReference, failureReference)
907:        . TLetD fail BX (TCon failureReference 0 [stack1, stack2])
917:        . TLetD fail BX (TCon failureReference 0 [stack1, stack2])
930:        . TLetD fail BX (TCon failureReference 0 [stack1, stack2])
943:        . TLetD fail BX (TCon failureReference 0 [stack1, stack2])
957:        . TLetD fail BX (TCon failureReference 0 [stack1, stack2])