Cabal format duplicates dependencies

[tfausak]

Running cabal format duplicates the build-depends section and duplicates dependencies in that section. For example, with this Cabal file:

name: example
version: 0
cabal-version: >=1.22.0.0
build-type: Simple
license: MIT
license-file: LICENSE.txt
maintainer: Taylor Fausak <[email protected]>
synopsis: TODO
description:
    TODO
category: Other

library
    build-depends:
        base ==4.*
    default-language: Haskell2010

Repeatedly running cabal format produces this:

    build-depends:
        base ==4.*
    build-depends:
        base ==4.*

    build-depends:
        base ==4.*,
        base ==4.*
    build-depends:
        base ==4.*,
        base ==4.*

    build-depends:
        base ==4.*,
        base ==4.*,
        base ==4.*,
        base ==4.*
    build-depends:
        base ==4.*,
        base ==4.*,
        base ==4.*,
        base ==4.*

I would expect cabal format to not make any changes to the given Cabal file. I'm using GHC version 7.8.3 and Cabal version 1.22.0.0.

[tibbe]

/cc @benarmston

On Mon, Jan 12, 2015 at 4:33 PM, Taylor Fausak [email protected]
wrote:

Running cabal format duplicates the build-depends section and duplicates
dependencies in that section. For example, with this Cabal file:

name: example
version: 0
cabal-version: >=1.22.0.0
build-type: Simple
license: MIT
license-file: LICENSE.txt
maintainer: Taylor Fausak [email protected]
synopsis: TODO
description:
TODO
category: Other

library
build-depends:
base ==4.*
default-language: Haskell2010

Repeatedly running cabal format produces this:

build-depends:
    base ==4.*
build-depends:
    base ==4.*

build-depends:
    base ==4.*,
    base ==4.*
build-depends:
    base ==4.*,
    base ==4.*

build-depends:
    base ==4.*,
    base ==4.*,
    base ==4.*,
    base ==4.*
build-depends:
    base ==4.*,
    base ==4.*,
    base ==4.*,
    base ==4.*

I would expect cabal format to not make any changes to the given Cabal
file. I'm using GHC version 7.8.3 and Cabal version 1.22.0.0.

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#2353.

[tfausak]

I think the problem is in showGenericPackageDescription, but I'm not at all familiar with Cabal. I used this script to try some things out:

import Distribution.ParseUtils (ParseResult (ParseOk))
import Distribution.PackageDescription.Parse (parsePackageDescription)
import Distribution.PackageDescription.PrettyPrint (showGenericPackageDescription)

main :: IO ()
main = case parsePackageDescription cabalFile of
    ParseOk _ package -> do
        print package
        putStrLn (showGenericPackageDescription package)
    _ -> return ()

cabalFile :: String
cabalFile = unlines
    [ "name: example"
    , "cabal-version: >=1.2"
    , "license: UnspecifiedLicense"
    , ""
    , "library"
    , "    build-depends:"
    , "        base -any"
    ]

Running that gave me this output:

GenericPackageDescription {packageDescription = PackageDescription {package = PackageIdentifier {pkgName = PackageName {unPackageName = "example"}, pkgVersion = Version {versionBranch = [], versionTags = []}}, license = UnknownLicense "UnspecifiedLicense", licenseFiles = [], copyright = "", maintainer = "", author = "", stability = "", testedWith = [], homepage = "", pkgUrl = "", bugReports = "", sourceRepos = [], synopsis = "", description = "", category = "", customFieldsPD = [], buildDepends = [], specVersionRaw = Right (UnionVersionRanges (ThisVersion (Version {versionBranch = [1,2], versionTags = []})) (LaterVersion (Version {versionBranch = [1,2], versionTags = []}))), buildType = Nothing, library = Nothing, executables = [], testSuites = [], benchmarks = [], dataFiles = [], dataDir = "", extraSrcFiles = [], extraTmpFiles = [], extraDocFiles = []}, genPackageFlags = [], condLibrary = Just (CondNode {condTreeData = Library {exposedModules = [], reexportedModules = [], requiredSignatures = [], exposedSignatures = [], libExposed = True, libBuildInfo = BuildInfo {buildable = True, buildTools = [], cppOptions = [], ccOptions = [], ldOptions = [], pkgconfigDepends = [], frameworks = [], cSources = [], jsSources = [], hsSourceDirs = [], otherModules = [], defaultLanguage = Nothing, otherLanguages = [], defaultExtensions = [], otherExtensions = [], oldExtensions = [], extraLibs = [], extraGHCiLibs = [], extraLibDirs = [], includeDirs = [], includes = [], installIncludes = [], options = [], profOptions = [], sharedOptions = [], customFieldsBI = [], targetBuildDepends = [Dependency (PackageName {unPackageName = "base"}) AnyVersion], targetBuildRenaming = fromList [(PackageName {unPackageName = "base"},ModuleRenaming True [])]}}, condTreeConstraints = [Dependency (PackageName {unPackageName = "base"}) AnyVersion], condTreeComponents = []}), condExecutables = [], condTestSuites = [], condBenchmarks = []}
name: example
cabal-version: >=1.2
license: UnspecifiedLicense

library
    build-depends:
        base -any
    build-depends:
        base -any

The package description contains a lot of things, but this part looked interesting:

targetBuildDepends = [Dependency (PackageName {unPackageName = "base"}) AnyVersion]

There appears to only be one dependency. That tells me that it's being parsed correctly but it's being displayed incorrectly.

[tfausak]

This still happens with cabal-install 1.22.0.1. From what I can tell, it only affects Cabal on OS X.

[tfausak]

This does not happen anymore with cabal-install 1.22.2.0. One of these changes fixed it: cabal-install-v1.22.0.1...cabal-install-v1.22.2.0.