Warning is emitted in reverse

[leana8959]

Describe the bug When cabal emits field grammar parser warnings, it does so in reverse. That is, a line comes later in a file comes earlier in the warning. This is inconsistent with ghc's default behaviour.

To Reproduce

• Write this to a cabal file

  cabal-version: 3.0
  name:          simple
  version:       0.1.0.0
  
  common a
    build-depends:
  
  library
    hs-source-dirs:     src
    exposed-modules:
      App
  
    import: a
    import: a
    import: a
    import: a
  

• Run

  $ cabal build
  

• The warning should be something like the following. Note how it goes from line 16 to 13. This is inconsistent with ghc's default behavior, for example.

  Resolving dependencies...
  Build profile: -w ghc-9.8.4 -O1
  In order, the following will be built (use -v for more details):
   - simple-0.1.0.0 (lib) (configuration changed)
  Warning: simple.cabal:16:3: Unknown field: import. Common stanza imports
  should be at the top of the enclosing section
  Warning: simple.cabal:15:3: Unknown field: import. Common stanza imports
  should be at the top of the enclosing section
  Warning: simple.cabal:14:3: Unknown field: import. Common stanza imports
  should be at the top of the enclosing section
  Warning: simple.cabal:13:3: Unknown field: import. Common stanza imports
  should be at the top of the enclosing section
  

Expected behavior The warnings should be in the same order as the file.

System information

• Linux 6.12.47, NixOS, 25.05 (Warbler), 872106a4
• cabal-install version 3.17.0.0 (commit 0c8d69f, Mon Nov 3 19:17:29 2025 +0000) compiled using version 3.17.0.0 of the Cabal library (in-tree)

Additional context Maybe someone forgot to flip the warnings accumulator?

[mpickering]

👍 Seems like a good improvement. Thanks for raising the ticket.