Allow overlap of term+type references during canonicalization - #6176
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Previously, the canonicalizer was written assuming that there would never be `Reference` values used for both terms and types, and would fail out if that happened. This is a safe assumption in actual practice, since it would involve either a hash collision or reused builtin references (which we don't have). However, test cases were sometimes being generated that violated this assumption. The new implementation instead behaves similarly to a completely new reference in these cases, adding to the tracked term/type maps. This means the function never fails.
aryairani
approved these changes
Feb 25, 2026
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@dolio Try and push those attestations/proofs when you have a chance. |
pchiusano
approved these changes
Feb 26, 2026
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Previously, the canonicalizer was written assuming that there would never be
Referencevalues used for both terms and types, and would fail out if that happened. This is a safe assumption in actual practice, since it would involve either a hash collision or reused builtin references (which we don't have). However, test cases were sometimes being generated that violated this assumption.The new implementation instead behaves similarly to a completely new reference in these cases, adding to the tracked term/type maps. This means the function never fails.
This should fix the occasional test failures. I'm actually surprised we didn't encounter one earlier, because it happened relatively often when I ran the specific test locally (and the fixed seed didn't seem to work, so I don't think it was that).