George Colpitts
It seems unlikely that the current tests wouldn't find this bug. Is it the case that the tests are never run on aarch64-darwin Macs?
The tests are certainly run; see, for instance, the 9.8.1-alpha4 release pipeline [1]. The problem is that #21570 requires very particular (mis)configuration of the host toolchain (e.g. Richard had multiple, incompatible toolchains in PATH). We can usually side-step this sort of misconfiguration by disabling the `configure` script's ld-override logic, since we using anything but Apple's linker is generally a bad idea on Darwin. This measure (!8437) is present in the 9.8 branch so I can only guess that something else is wrong. Perhaps you could open a ticket and attach config.log? Cheers, - Ben [1]: https://gitlab.haskell.org/ghc/ghc/-/jobs/1668689