There's a couple of wrong function signatures in dictobject.c,

dictkeys_reversed and dictitems_reversed are defined as single arg functions like so: PyObject *(PyObject *), and are then passed around and called as PyCFunctions, which should be PyObject *(PyObject *self,PyObject *args). dictvalues_reversed is correct.

This works fine on most C compilers as the extra arg is just ignored, but on things that use strict function pointer type checking (e.g. webassembly), it crashes (and hence any of the tests that happen to use these functions fails, which is a surprising number)

I've got a fix in my pyodide repo, which I'll chuck in as a pull request on github.

Good catch! The signature of dictkeys_reversed was already fixed (for purity reason), but the same bug in dictvalues_reversed and dictitems_reversed was missed. It is nice that such bugs can now be caught by tools.

New changeset 7cbe6ca63495d478a3164d6d26ef36cb611abbbb by Miss Islington (bot) in branch '3.10':
bpo-44114: Fix dictkeys_reversed and dictvalues_reversed function signatures (GH-26062)
https://github.com/python/cpython/commit/7cbe6ca63495d478a3164d6d26ef36cb611abbbb

New changeset 04c46101944777dd131bbfe8dbfef5f4d328860d by Miss Islington (bot) in branch '3.9':
bpo-44114: Remove redundant cast. (GH-26098)
https://github.com/python/cpython/commit/04c46101944777dd131bbfe8dbfef5f4d328860d

New changeset c4c3beb5ad6b55c20b6dc7c6a92860f467afa75b by Miss Islington (bot) in branch '3.10':
bpo-44114: Remove redundant cast. (GH-26098)
https://github.com/python/cpython/commit/c4c3beb5ad6b55c20b6dc7c6a92860f467afa75b

New changeset 925cb85e9e28d69be53db669527c0a1292f0fbfb by Miss Islington (bot) in branch '3.9':
bpo-44114: Fix dictkeys_reversed and dictvalues_reversed function signatures (GH-26062) (GH-26093)
https://github.com/python/cpython/commit/925cb85e9e28d69be53db669527c0a1292f0fbfb