Segfault in RISC-V programs built by a registerised GHC

Summary

Most interesting programs segfault when compiled by a registerised GHC. This also includes GHC itself when compiling non-trivial programs.

I have tried cross-compiling GHC 9.2.7, 9.4.5, and 9.6.2, but none of them worked. I have also tried natively compiling GHC 9.6.2 using an unregisterised cross-compiled 9.4.5, but that didn't work either.

Steps to reproduce

Using Nix:

nix-build -p 'pkgsCross.riscv64.haskell.compiler.native-bignum.ghc945' -I nixpkgs=https://github.com/AlexandreTunstall/nixpkgs/archive/40f2e8f3abc55ff292cc3328ff22d4159893ad20.tar.gz

Then try using the resulting GHC to compile pandoc (this may require binfmt emulation or a RISC-V system).

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Without Nix:

1. Compile one of the affected versions registerised for RISC-V (both cross and native should reproduce this issue)
2. Try using the stage 2 compiler to compile non-trivial software (e.g. pandoc).

I might not have tested native compilation properly, but it can definitely be reproduced with cross.

Expected behavior

pandoc compiles successfully; this is the case with unregisterised GHC.

Observed behavior

A segmentation fault with no additional details at some early stage of compiling pandoc.

Environment

• GHC version used: 9.2.7, 9.4.5, and 9.6.2

Optional:

• Operating System: Linux
• System Architecture: RV64GC (cross) and RV64GC_Zba_Zbb (native)