Have `make style` ignore well-known build dirs

[philderbeast]

Can we have make style ignore well-known build directories like dist-newstyle and .stack-work?

$ make style
Cabal-syntax/.stack-work/dist/x86_64-linux/ghc-8.10.7/build/Distribution/Fields/Lexer.hs:45:1
  The GHC parser (in Haddock mode) failed:
  [GHC-58481] parse error on input `#'
make: *** [Makefile:32: style] Error 102

[ffaf1]

This is a good suggestion, are you aware of style-modified? Does it output the same error?

[philderbeast]

Running make style-modified seems fine, no output and no error.

[ffaf1]

Your suggestion is still good, and I wonder if it has something to do with git ignores.

[9999years]

@philderbeast If you don't already have one set up, you might consider a global Gitignore.

(NB: I have no clue if fourmolu actually checks the Gitignore or just does a naïve directory traversal.)

[philderbeast]

Thanks @9999years, I tried committing an expansion of the .stack-work glob to include all such directories. This didn't change the make style behaviour, it still choked on the same file.

$ git diff HEAD~1 HEAD
diff --git a/.gitignore b/.gitignore

--- a/.gitignore
+++ b/.gitignore
 
 # stack artifacts
-/.stack-work/
+**/.stack-work/
 stack.yaml.lock

I see fourmolu-0.13.0.0 fixes this problem but we're on an earlier version.

Fourmolu 0.13.0.0

• Automatically ignore files in Cabal/Stack directories when recursively finding files to format.
  Changelog for fourmolu-0.13.0.0

$ fourmolu --version
fourmolu 0.12.0.0
using ghc-lib-parser 9.6.6.20240701

[philderbeast]

I have another reproduction, the make check rule depends on make style so this also triggers the problem.

[9999years]

I've created a new label for code formatting issues: re: code formatting Automated code formatting with Fourmolu or similar

I believe there's some work happening with Fourmolu that might interfere with this; see #9424

[philderbeast]

After trying #10259, I was left with a file that messed up hlint:

$ hlint --default .
Warning: Can't find file "ghcconfig.h" in directories
	./dist-newstyle.apigen/build/x86_64-linux/ghc-9.10.1/Cabal-syntax-3.15.0.0/build/Distribution/Fields
	.
  Asked for by: ./dist-newstyle.apigen/build/x86_64-linux/ghc-9.10.1/Cabal-syntax-3.15.0.0/build/Distribution/Fields/Lexer.hs  at line 46 col 1