Only install handlers when HAVE_SIGNAL_H

[amesgen]

This allows to run test suites on platforms that do not support signals, such as the new WASM backend in GHC 9.6.

[andreasabel]

Is there a way to test this change?

[Bodigrim]

@amesgen would it be possible to add something like https://github.com/haskell/unix/blob/master/.github/workflows/ci-wasm32-wasi.yml ?

[amesgen]

@amesgen would it be possible to add something like https://github.com/haskell/unix/blob/master/.github/workflows/ci-wasm32-wasi.yml ?

Yeah, I will try to add something here 👍

[amesgen]

I pushed a commit running all tests except the resource-release-test as it depends on signals (which WASM/WASI does not have ATM).

Depends on haskellari/splitmix#73 as splitmix is a transitive test dependency.

@TerrorJack if you want to take a look: Given your blog post, is there a nicer way to treat WASM files as executables in PATH than in this PR?

[TerrorJack]

@amesgen The proot trick described in the blog post is really a huge hack that was only meant to be used before the ghc testsuite didn't support cross emulators, and I think it's better to not use that in this PR.

There is one little potential improvement: instead of your own wrapper script that calls wasmtime, you are recommended to use ~/.ghc-wasm/wasm-run/bin/wasmtime.sh foo.wasm --command_line_args instead. That wrapper script is what I use for the ghc testsuite; it automatically adds wasmtime flags to set up the filesystem, current directory and such.

[amesgen]

There is one little potential improvement: instead of your own wrapper script that calls wasmtime, you are recommended to use ~/.ghc-wasm/wasm-run/bin/wasmtime.sh foo.wasm --command_line_args instead.

This works great locally, but on GHA, exit-status-tests.sh fails:

+ timeout 3 exit-status-test --result=False --slow=3 --fast=0 --num-threads=4 --quiet
+ [ 124 -eq 1 ]

I guess that this is due to one of the additional flags in wasmtime.sh. So I will leave it as is for now.

[andreasabel]

Thanks, great work!

Some suggestion on the cache key for the new CI job.

[andreasabel]

matrix.ghc is undefined here, as there is no matrix strategy for this job.

I recommend actionlint to find such problems statically.

Also, the key should have component pertaining to the job, e.g.:

key: build-wasi-${{ runner.os }}-ghc-${{ env.FLAVOUR }}-sha-${{ github.sha }}

[amesgen]

Good catch, thanks for the pointer to actionlint! Should now be fixed; I also pinned ghc-wasm-meta and included the rev in the cache key 👍

[andreasabel]

Thanks for the fixes to caching!