Components update

[kczulko]

• nixpkgs so now it is using bazel 4.2.1:
  https://lazamar.co.uk/nix-versions/?channel=nixos-unstable&package=bazel
• rules_haskell to latest release
• rules_go to 0.30.0
• ghc to 8.10.7

[kczulko]

@facundominguez

I don't like one thing here... I added git to the nix-shell since it is somehow required by rules_haskell (probably transitively by rules_sh (?) ). Should I use rules_sh or rules_nixpkgs to add git executable to the PATH instead of this dirty nix-shell entry?

[nix-shell:~/Projects/gazelle_cabal]$ bazel run //cabalscan
Starting local Bazel server and connecting to it...
INFO: Repository rules_sh instantiated at:
  /home/kczulko/Projects/gazelle_cabal/WORKSPACE:18:27: in <toplevel>
  /home/kczulko/.cache/bazel/_bazel_kczulko/6be991cd39efcb35914245cec4088a8d/external/rules_haskell/haskell/repositories.bzl:50:10: in rules_haskell_dependencies
  /home/kczulko/.cache/bazel/_bazel_kczulko/6be991cd39efcb35914245cec4088a8d/external/bazel_tools/tools/build_defs/repo/utils.bzl:201:18: in maybe
Repository rule git_repository defined at:
  /home/kczulko/.cache/bazel/_bazel_kczulko/6be991cd39efcb35914245cec4088a8d/external/bazel_tools/tools/build_defs/repo/git.bzl:199:33: in <toplevel>
ERROR: An error occurred during the fetch of repository 'rules_sh':
   Traceback (most recent call last):
	File "/home/kczulko/.cache/bazel/_bazel_kczulko/6be991cd39efcb35914245cec4088a8d/external/bazel_tools/tools/build_defs/repo/git.bzl", line 181, column 30, in _git_repository_implementation
		update = _clone_or_update(ctx)
	File "/home/kczulko/.cache/bazel/_bazel_kczulko/6be991cd39efcb35914245cec4088a8d/external/bazel_tools/tools/build_defs/repo/git.bzl", line 36, column 20, in _clone_or_update
		git_ = git_repo(ctx, directory)
	File "/home/kczulko/.cache/bazel/_bazel_kczulko/6be991cd39efcb35914245cec4088a8d/external/bazel_tools/tools/build_defs/repo/git_worker.bzl", line 91, column 12, in git_repo
		_update(ctx, git_repo)
	File "/home/kczulko/.cache/bazel/_bazel_kczulko/6be991cd39efcb35914245cec4088a8d/external/bazel_tools/tools/build_defs/repo/git_worker.bzl", line 101, column 9, in _update
		init(ctx, git_repo)
	File "/home/kczulko/.cache/bazel/_bazel_kczulko/6be991cd39efcb35914245cec4088a8d/external/bazel_tools/tools/build_defs/repo/git_worker.bzl", line 118, column 15, in init
		_error(ctx.name, cl, st.stderr)
	File "/home/kczulko/.cache/bazel/_bazel_kczulko/6be991cd39efcb35914245cec4088a8d/external/bazel_tools/tools/build_defs/repo/git_worker.bzl", line 190, column 9, in _error
		fail("error running '%s' while working with @%s:\n%s" % (command_text, name, stderr))
Error in fail: error running 'git init /home/kczulko/.cache/bazel/_bazel_kczulko/6be991cd39efcb35914245cec4088a8d/external/rules_sh' while working with @rules_sh:
src/main/tools/process-wrapper-legacy.cc:80: "execvp(git, ...)": No such file or directory

Best regards,
Karol

[facundominguez]

Hello! Do you know what dependency update requires git to be in the PATH and what for?

[aherrmann]

It looks like rules_haskell now depends on rules_sh via git_repository instead of http_archive. Switching this back to http_archive should avoid the dependency on git.

[kczulko]

Indeed:

https://github.com/tweag/rules_haskell/blob/master/haskell/repositories.bzl#L51

I'll ask @ylecornec if I can revert it to http_archive. I wanted to put some "stable, latest release" version for our rules_haskell dependency but well.. :)

[facundominguez]

Thanks @aherrmann! If that's all, I think it is pretty ok to add git to shell.nix.

[facundominguez]

Thanks @kczulko!