rts dependency in cc_library no longer works (can't find HsFFI.h)

Question

rts dependency in cc_library no longer works (can't find HsFFI.h)

iphydf opened this issue 10 months ago · 5 comments

Describe the bug
I have a cc_library with a file that includes HsFFI.h. It depends on the rts haskell_toolchain_library. As of some commit around the range of the two commits below, that include fails:

c-toxcore-hs/src/hsbracket.c:1:10: fatal error: 'HsFFI.h' file not found

To Reproduce
Commit d14584e is fine.
Commit 895a4a2 is broken.

Environment

OS name + version: NixOS 23.11
Bazel version: 6.4.0
Version of the rules: See above.

Additional context
I tried roughly bisecting the git history but didn't investigate a lot. The git history is very non-linear, so the linear github view is a bit confusing. I didn't look at the actual git repo.

Answer 1 · 2024-01-02T10:30:52.000Z

Thank you for the report! Which version of GHC are you using? And which revision of nixpkgs are you at (assuming you're using rules_nixpkgs)?

Perhaps you can create a minimal reproducible example, since we ensure this works for GHC 9.2.8, 9.4.6 and 9.6.2 in https://github.com/tweag/rules_haskell/tree/master/rules_haskell_tests/tests/cc_haskell_import ?

Answer 2 · 2024-01-02T11:48:24.000Z

My BUILD.bazel: https://github.com/TokTok/c-toxcore-hs/blob/1394e667b39ce6079289720fd1ed6276f80add60/BUILD.bazel
rts import: https://github.com/TokTok/toktok-stack/blob/master/third_party/haskell/BUILD.bazel#L75
rules_haskell load: https://github.com/TokTok/toktok-stack/blob/master/WORKSPACE#L111

I don't have a small repro yet. I can probably look into that later this week, maybe in the weekend. Is there any debug info I can provide that would help pinpoint the issue?

Answer 3 · 2024-01-02T13:09:57.000Z

Could you run bazel cquery --output build @rules_haskell_ghc_nixpkgs_haskell_toolchain//:rts and post the output?

Answer 4 · 2024-01-02T13:35:23.000Z

Working (old version): https://gist.github.com/iphydf/7acc533910257c2a2c2e1e046176c9bd

Not working (current master): https://gist.github.com/iphydf/b34dad2d4a4dc82fac58a4910e4abf0e

Answer 5 · 2024-01-03T07:41:31.000Z

Thank you! It's now pretty obvious why it cannot work, since the includes and hdrs attributes are all empty in the output:

# /home/builder/.cache/bazel/_bazel_builder/a08c2e4811c846650b733c6fc815a920/external/rules_haskell_ghc_nixpkgs_haskell_toolchain/BUILD:1365:15
haskell_import(
  name = "rts",
  visibility = ["//visibility:public"],
  id = "rts",
  version = "1.0.2",
  deps = [],
  static_libraries = [],
  shared_libraries = [],
  static_profiling_libraries = [],
  linkopts = ...,
  hdrs = [],
  includes = [],
  haddock_interfaces = [],
)

Maybe this is related to using ghcWithPackages, which we do not yet test against. I'll have a look.