This package provides a Cabal post-build hook for building application bundles for GUIs on Mac OSX. It also includes a standalone command line utility (macosx-app) for wrapping one-off GUIs that do not use Cabal.

Under Mac OSX, graphical applications require certain infrastructure in order to run properly: you can't just build an executable and run it (as on Linux, say), but must instead wrap it up in an application bundle, which is a directory having certain structure and marked as an app using a particular tool. This package provides Cabal post-build hook infrastructure for creating such bundles automatically, optionally including icons, other resources, and even local copies of shared libraries (for building apps which may be distributed standalone).

The command line version only provides basic functionality at the moment. It takes a single argument, the path to an executable, and produces an application bundle in the current working directory.

To add cabal-macosx to your project with Cabal 1.24 or higher, add a custom-setup section with cabal-macosx as a dependency. For example,

custom-setup
  setup-depends: base >= 4.9 && < 5
               , Cabal >= 1.24 && < 1.25
               , cabal-macosx >= 0.2 && < 0.3

And modify your Setup.hs to call the cabal-macosx post-build hook:

import Distribution.MacOSX
import Distribution.Simple

main :: IO ()
main = defaultMainWithHooks $ simpleUserHooks
  { postBuild = appBundleBuildHook guiApps
  }

guiApps :: [MacApp]
guiApps =
  [ MacApp
    { appName = "MyApp"
    , appIcon = Just "icon.icns"
    , appPlist = Nothing -- Build a default Info.plist for the icon.
    , resources = [] -- No other resources.
    , otherBins = [] -- No other binaries.
    , appDeps = DoNotChase -- Try changing to ChaseWithDefaults
    }
  ]

See the Hackage documentation for details on the build hook API.

For more examples please visit cabal-macosx-examples.

If you are using Stack, add the current version of cabal-macosx to the extra-deps section of your stack.yaml. For example,

extra-deps:
- cabal-macosx-0.2.3.5

As of Stack 1.3.2, Cabal's custom-setup section is not yet supported, so you will also need to add cabal-macosx to your executable's main dependency list in your .cabal file,

executable MyApp
  build-depends: base >= 4.9 && < 5
               , Cabal >= 1.24 && < 1.25
               , cabal-macosx >= 0.2 && < 0.3

and add an explicit-setup-deps section to your stack.yaml:

explicit-setup-deps:
  "*": true

(custom-setup is implemented in Stack's latest master and will hopefully be in a future release.)

To include resource files in an app bundle, add their paths relative to the project root to the resources field of your MacApp. Access these resources from your application by using the executable-path package, for example:

readLicense = do
  exePath <- getExecutablePath
  let contentsPath = takeDirectory (takeDirectory exePath)
  readFile (contentsPath </> "Resources/LICENSE")

Do not access resources in your application by relative path without changing your working directory first, as the working directory that GUI applications are started in is not specified.

If you get an error similar to this:

exited with an error:

dist/dist-sandbox-8121acba/setup/setup.hs:11:19:
Couldn't match type ‘LocalBuildInfo’
with ‘Cabal-1.22.5.0:Distribution.Simple.LocalBuildInfo.LocalBuildInfo’
NB: ‘LocalBuildInfo’
is defined in ‘Distribution.Simple.LocalBuildInfo’
in package ‘Cabal-1.22.6.0’
‘Cabal-1.22.5.0:Distribution.Simple.LocalBuildInfo.LocalBuildInfo’
is defined in ‘Distribution.Simple.LocalBuildInfo’
in package ‘Cabal-1.22.5.0’
Expected type: Args
-> Distribution.Simple.Setup.BuildFlags
-> Distribution.PackageDescription.PackageDescription
-> LocalBuildInfo
-> IO ()
Actual type: [String]
-> Cabal-1.22.5.0:Distribution.Simple.Setup.BuildFlags
-> Cabal-1.22.5.0:Distribution.PackageDescription.PackageDescription
-> Cabal-1.22.5.0:Distribution.Simple.LocalBuildInfo.LocalBuildInfo
-> IO ()
In the ‘postBuild’ field of a record
In the second argument of ‘($)’, namely
‘simpleUserHooks {postBuild = myPostBuild}’
)

You might need to update your version of Cabal with something like this:

~$ cabal --version
cabal-install version 1.22.6.0
using version 1.22.4.0 of the Cabal library
~$ cabal update
...
~$ cabal install cabal cabal-install
...
~$ cabal --version
cabal-install version 1.22.7.0
using version 1.22.6.0 of the Cabal library

More: https://www.haskell.org/cabal/download.html

If you get an error similar to this:

LSOpenURLsWithRole() failed with error -10810 for the file...

This may be because your program is exiting or crashing immediately during launch.

If your application runs normally when run directly from the terminal, it may be that your application is depending on being launched from a particular working directory or with a certain set of environment variables. For example, loading resource files by relative path or running programs only on your shell's PATH. Applications started in a GUI context (such as from open or the Finder) run in an unspecified working directory and a standard set of environment variables that are not derived from your shell.

To view your application's standard output and standard error when run from a GUI context, use the system Console app (found in /Applications/Utilities).

This code was branched from https://code.haskell.org/GenI/Setup.hs and https://www.mail-archive.com/[email protected]/msg00701.html

The package is extensively documented, including internally. If you're interested in modifying it, you may want to

runghc Setup haddock --hyperlink-source --internal

to produce full internal documentation.

Daniele Francesconi - 2015.12.29

Andy Gimblett - 2010.02.16