How can this be used via stack?

[tonyalaribe]

Hi, I followed the readme tutorial and it worked perfectly.
But I've unable to reproduce this with stack and always run into the error:

rust-interop     > .stack-work/dist/aarch64-osx/ghc-9.8.1/build/librust_interop.a: copyFile: does not exist (No such file or directory)

Following the step steps, except using the stack.yaml to configure extra-deps from the parent haskell project, to the other haskell+rust library created according to the tutorial.

Do you have any pointers on what I should do to make this work with stack (no cabal.project file)?

I added the following to the package.yaml (hpack used by stack), and it doesn't solve the errors

library:
  extra-lib-dirs:
    - ${pkgroot}/rust-interop/target/debug
  extra-libraries: 
    - rust_interop
  source-dirs: 
    - src
    - rust-interop/src

[tonyalaribe]

I can confirm that librust_interop.a exists within the project, compile with the rust cargo

[tonyalaribe]

So, I checked the stack-works directory and found .a files, but with a weird file name which is different from what the error mention. So I copied and renamed the .a files

from libHSrust-interop-0.1.0-A5y6IDrTtmR7YRBdfq8J7z.a to librust_interop.a
withing the directory .stack-work/dist/aarch64-osx/ghc-9.8.1/build/

Now the error is

ghc-9.8.1: panic! (the 'impossible' happened)
  GHC version 9.8.1:
        Don't understand library name rust_interop
  CallStack (from HasCallStack):
    panic, called at compiler/GHC/Unit/Info.hs:226:15 in ghc-9.8.1-a76c:GHC.Unit.Info

I'm unsure how to investigate or figure this out. So I would appreciate any pointers

[tchoutri]

Hi @tonyalaribe :)

You can see some things in this PR: #5, especially how Domen did it.

[tonyalaribe]

Hi @tchoutri 👋

Oh, I have to check out Domen's work in better detail. But for now, I solved the problem by using a makefile which copies and renames the dylib files.

That error is kinda interesting.

ghc-9.8.1: panic! (the 'impossible' happened)
  GHC version 9.8.1:
        Don't understand library name rust_interop

Basically, GHC expects the libs to be prefixed with either C or HS. If none of those prefixes is present, then we get the error.

My Makefile looks like this now:

GHC_VERSION := 9.8.1
ARCH := $(shell uname -m | sed 's/arm64/aarch64/' | tr '[:upper:]' '[:lower:]')
OS := $(shell uname -s | sed 's/Darwin/osx/' | tr '[:upper:]' '[:lower:]')
OS_ARCH := $(ARCH)-$(OS)
RUSTLIB := rust_interop

prepare-rust-interop:
	cd ./rust-interop/ && \
	cargo build --release && \
	mkdir -p ./.stack-work/dist/$(OS_ARCH)/ghc-$(GHC_VERSION)/build/ && \
	cp ./target/release/lib$(RUSTLIB).a .stack-work/dist/$(OS_ARCH)/ghc-$(GHC_VERSION)/build/libC$(RUSTLIB).a || true && \
	cp ./target/release/lib$(RUSTLIB).so .stack-work/dist/$(OS_ARCH)/ghc-$(GHC_VERSION)/build/libC$(RUSTLIB).so || true && \
	cp ./target/release/lib$(RUSTLIB).so .stack-work/dist/$(OS_ARCH)/ghc-$(GHC_VERSION)/build/libC$(RUSTLIB)-ghc$(GHC_VERSION).so || true && \
	cp ./target/release/lib$(RUSTLIB).dylib .stack-work/dist/$(OS_ARCH)/ghc-$(GHC_VERSION)/build/libC$(RUSTLIB).dylib || true && \
	cp ./target/release/lib$(RUSTLIB).dylib .stack-work/dist/$(OS_ARCH)/ghc-$(GHC_VERSION)/build/libC$(RUSTLIB)-ghc$(GHC_VERSION).dylib  || true