T1407 sometimes fails in unregisterised way

I have observed it fail like this:

--- /dev/null	2021-01-17 06:28:05.166785577 +0000
+++ "/builds/ghc/ghc/tmp/ghctest-jvfyy4xs/test   spaces/testsuite/tests/ghci/linking/dyn/T1407.run/T1407.run.stderr.normalised"	2021-01-17 08:13:49.010828433 +0000
@@ -0,0 +1 @@
+*** Exception: prepForeignCallFailed: invalid type description (FFI_BAD_TYPEDEF)(cconv: FFICCall arg tys: [] res ty: FFISInt32)

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