Add Haskell rules to the CI

[laurentlb]

I think this should be added to the CI: https://github.com/tweag/rules_haskell

[laurentlb]

According to @mboes, Haskell rules should be easier to integrate to the CI
(tweag/rules_haskell#489 (comment))

@philwo, how do we add the rules to the CI?

[philwo]

I'll add them to CI in the next days.

[laurentlb]

Thanks!
See also this comment by @Profpatsch: tweag/rules_haskell#754 (comment)

[Profpatsch]

@philwo Any success? If you want we can pair on this.

[philwo]

Thanks for the reminder.

I created a pipeline now: https://buildkite.com/bazel/rules-haskell-haskell
It's pulling from a personal fork of rules_haskell where I added a basic configuration file: https://github.com/philwo/rules_haskell/commit/8fb6c6c28a676686d5f8ae1817c09ed4c8e7cb4f
The first build failed with: "can't load .so/.DLL for: libgmp.so (libgmp.so: cannot open shared object file: No such file or directory)" (https://buildkite.com/bazel/rules-haskell-haskell/builds/2#29f8db4f-40dd-49e9-8193-fdb6790a1f64)

This is probably due to a missing package. I'll add it to our Docker container and will try again, but I'm about to go on vacation for a week, so I probably won't get to this before June 24th. I setup a reminder to pop-up in my inbox on that day.

@Profpatsch Once I get the basics working, we can iterate together to make it all work. :) One question already: It seems like you're running tests not by simply running "bazel test ..." but via a shell script. That's not really supported on our CI. However, we can run a shell script (or: any shell commands) before running the "bazel build" and "bazel test" commands. Maybe we can get it working using that mechanism.

[Profpatsch]

The first build failed with: "can't load .so/.DLL for: libgmp.so (libgmp.so: cannot open shared object file: No such file or directory)"

These are the dependencies needed by dynamically linked GHC:

$ ldd /nix/store/6mhw5wfnmncfbgghvbavhxadr9wq62i6-ghc-8.6.4/lib/ghc-8.6.4/bin/ghc | grep -v libHS
	linux-vdso.so.1 (0x00007fff395c4000)
	libm.so.6 => /nix/store/681354n3k44r8z90m35hm8945vsp95h1-glibc-2.27/lib/libm.so.6 (0x00007fe3a06b7000)
	libncursesw.so.6 => /nix/store/9yn8h9fvpfvrz9a3bqzjzz291mz08mqp-ncurses-6.1-20190112/lib/libncursesw.so.6 (0x00007fe399b7a000)
	librt.so.1 => /nix/store/681354n3k44r8z90m35hm8945vsp95h1-glibc-2.27/lib/librt.so.1 (0x00007fe399b70000)
	libutil.so.1 => /nix/store/681354n3k44r8z90m35hm8945vsp95h1-glibc-2.27/lib/libutil.so.1 (0x00007fe399b69000)
	libdl.so.2 => /nix/store/681354n3k44r8z90m35hm8945vsp95h1-glibc-2.27/lib/libdl.so.2 (0x00007fe399b64000)
	libpthread.so.0 => /nix/store/681354n3k44r8z90m35hm8945vsp95h1-glibc-2.27/lib/libpthread.so.0 (0x00007fe399b43000)
	libgmp.so.10 => /nix/store/l0svq68vy8zx8i0fiffyqchng6xhx0an-gmp-6.1.2/lib/libgmp.so.10 (0x00007fe399aad000)
	libffi.so.6 => /nix/store/djzkfv5r10b19vyhnqxzwijjhhxq6i22-libffi-3.2.1/lib/libffi.so.6 (0x00007fe399aa0000)
	libc.so.6 => /nix/store/681354n3k44r8z90m35hm8945vsp95h1-glibc-2.27/lib/libc.so.6 (0x00007fe3998ea000)
	/nix/store/681354n3k44r8z90m35hm8945vsp95h1-glibc-2.27/lib/ld-linux-x86-64.so.2 => /nix/store/681354n3k44r8z90m35hm8945vsp95h1-glibc-2.27/lib64/ld-linux-x86-64.so.2 (0x00007fe3a0851000)

One question already: It seems like you're running tests not by simply running "bazel test ..." but via a shell script. That's not really supported on our CI.

Yes, we are using this to chain multiple calls to bazel and get a nice test suite output. Can you run multiple different bazel calls in your setup?
Ideally, all of these would be moved into bazel rules/targets/genrules of course.

[mboes]

These are the dependencies needed by dynamically linked GHC:

This list is not informative. @philwo here are the dependencies of ghc on Ubuntu:

  Depends: gcc
  Depends: libgmp-dev
  Depends: libffi-dev
  Depends: libbsd-dev
  Depends: libc6-dev
  Depends: libncurses5-dev
  Depends: libc6
  Depends: libffi6
  Depends: libgmp10
  Depends: libtinfo5

[guibou]

Yes, we are using this to chain multiple calls to bazel and get a nice test suite output. Can you run multiple different bazel calls in your setup?
Ideally, all of these would be moved into bazel rules/targets/genrules of course.

In a perfect world, yes. But just running bazel test //... is better than nothing. I recently migrated rules_haskell from bazel 0.24 to bazel 0.27 and bazel test //... shows me most of the issues.

So I highly encourage starting with bazel test //... at first.

[laurentlb]

@philwo Is there still any blocker?

[Profpatsch]

@laurentlb We have a successful build on the CI now: tweag/rules_haskell#1099 (CI log: https://buildkite.com/bazel/rules-haskell-haskell/builds/109)

I think we’re ready to be added to your list of downstream projects.

cc @philwo @fweikert @mboes

[fweikert]

Done! Let me know if you have any further questions :)