PAP object entered under GHC 9.0.2

Summary

Under GHC 9.0.2 we had one of our programs crash with the following message:

pap: internal error: PAP object (0x42000069e8) entered!
    (GHC version 9.0.2 for x86_64_unknown_linux)
    Please report this as a GHC bug:  https://www.haskell.org/ghc/reportabug

One of my colleagues was able to write a relatively small reproducer. The crash does not occur on GHC 9.2 and 9.4.

Steps to reproduce

See this repo which includes a nix file for easy reproduction. Run nix-build to reproduce the crash.

Expected behavior

Run forever

Environment

• GHC version used: 9.0.2

Optional:

• Operating System: NixOS 21.11
• System Architecture: x64