Failure to link c-sources during template haskell on windows

[asivitz]

Describe the bug
MODULE1: Uses template haskell. References MODULE2 (e.g. by importing some definition from there)
MODULE2: In addition to the definition needed by MODULE1, it includes a FFI import (of a symbol defined in a .c file).

On Windows, this does not successfully compile. On Mac, this compiles without issue.

Examining -v3 output, the .c file appears to build after the Haskell modules. On Mac this isn't a problem. On Windows, running TH fails when it can't link the symbol that it should eventually find the in the .c file.

To Reproduce
Steps to reproduce the behavior (on windows):
Clone this repo: https://github.com/asivitz/windows_link_error

$ cabal build

Additionally, a build log of a Github action is available here: https://github.com/asivitz/windows_link_error/actions/runs/16758169600/job/47446201028

Expected behavior
Should build without error.

System information

• Windows 10
• GHCs 9.8.4-9.12.2 (and perhaps others).
• cabal-installs 3.10.3-3.16.0.0 (and perhaps others).

Additional context
The following cabal-less one-liner succeeds on both windows and mac, which suggests to me this is a cabal issue:

ghc -package base -package template-haskell -iSmall Small/Dep.hs Small/Foo.hs foreign_fun.c

Is there a reason we wouldn't just build the .c files first, before any haskell modules? Seems like that could be a straightforward fix.

Thank you!