Modules and preprocessors

Haskell module names listed in the exposed-modules and other-modules fields may correspond to Haskell source files, i.e. with names ending in “.hs” or “.lhs”, or to inputs for various Haskell preprocessors. The simple build infrastructure understands the extensions:

• .gc (greencard)
• .chs (c2hs)
• .hsc (hsc2hs)
• .y and .ly (happy)
• .x (alex)
• .cpphs (cpphs)

When building, Cabal will automatically run the appropriate preprocessor and compile the Haskell module it produces.

Some fields take lists of values, which are optionally separated by commas, except for the build-depends field, where the commas are mandatory.

Some fields are marked as required. All others are optional, and unless otherwise specified have empty default values.

Package properties

These fields may occur in the first top-level properties section and describe the package as a whole:

name: package-name (required)

The unique name of the package, without the version number.

version: numbers (required)

The package version number, usually consisting of a sequence of natural numbers separated by dots.

cabal-version: >= x.y

The version of the Cabal specification that this package description uses. The Cabal specification does slowly evolve, intoducing new features and occasionally changing the meaning of existing features. By specifying which version of the spec you are using it enables programs which process the package description to know what syntax to expect and what each part means.

For historical reasons this is always expressed using _>=_ version range
syntax. No other kinds of version range make sense, in particular upper
bounds do not make sense. In future this field will specify just a version
number, rather than a version range.

The version number you specify will affect both compatability and
behaviour. Most tools (including the Cabal libray and cabal program)
understand a range of versions of the Cabal specification. Older tools
will of course only work with older versions of the Cabal specification.
Most of the time, tools that are too old will recognise this fact and
produce a suitable error message.

As for behaviour, new versions of the Cabal spec can change the meaning
of existing syntax. This means if you want to take advantage of the new
meaning or behaviour then you must specify the newer Cabal version.
Tools are expected to use the meaning and behaviour appropriate to the
version given in the package description.

In particular, the syntax of package descriptions changed significantly
with Cabal version 1.2 and the `cabal-version` field is now required.
Files written in the old syntax are still recognized, so if you require
compatability with very old Cabal versions then you may write your package
description file using the old syntax.  Please consult the user's guide of
an older Cabal version for a description of that syntax.

build-type: identifier

The type of build used by this package. Build types are the constructors of the BuildType type, defaulting to Custom. If this field is given a value other than Custom, some tools such as cabal-install will be able to build the package without using the setup script. So if you are just using the default Setup.hs then set the build type as Simple.

license: identifier (default: AllRightsReserved)

The type of license under which this package is distributed. License names are the constants of the License type.

license-file: filename

The name of a file containing the precise license for this package. It will be installed with the package.

copyright: freeform

The content of a copyright notice, typically the name of the holder of the copyright on the package and the year(s) from which copyright is claimed. For example: Copyright: (c) 2006-2007 Joe Bloggs

author: freeform

The original author of the package.

Remember that `.cabal` files are Unicode, using the UTF-8 encoding.

maintainer: address

The current maintainer or maintainers of the package. This is an e-mail address to which users should send bug reports, feature requests and patches.

stability: freeform

The stability level of the package, e.g. alpha, experimental, provisional, stable.

homepage: URL

The package homepage.

bug-reports: URL

The URL where users should direct bug reports. This would normally be either:

* A `mailto:` URL, eg for a person or a mailing list.

* An `http:` (or `https:`) URL for an online bug tracking system.

For example Cabal itself uses a web-based bug tracking system

~~~~~~~~~~~~~~~~
bug-reports: http://hackage.haskell.org/trac/hackage/
~~~~~~~~~~~~~~~~

package-url: URL

The location of a source bundle for the package. The distribution should be a Cabal package.

synopsis: freeform

A very short description of the package, for use in a table of packages. This is your headline, so keep it short (one line) but as informative as possible. Save space by not including the package name or saying it’s written in Haskell.

description: freeform

Description of the package. This may be several paragraphs, and should be aimed at a Haskell programmer who has never heard of your package before.

For library packages, this field is used as prologue text by [`setup
haddock`](#setup-haddock), and thus may contain the same markup as
[haddock][] documentation comments.

category: freeform

A classification category for future use by the package catalogue Hackage. These categories have not yet been specified, but the upper levels of the module hierarchy make a good start.

tested-with: compiler list

A list of compilers and versions against which the package has been tested (or at least built).

data-files: filename list

A list of files to be installed for run-time use by the package. This is useful for packages that use a large amount of static data, such as tables of values or code templates. Cabal provides a way to find these files at run-time.

A limited form of `*` wildcards in file names, for example
`data-files: images/*.png` matches all the `.png` files in the
`images` directory.

The limitation is that `*` wildcards are only allowed in place of
the file name, not in the directory name or file extension.  In
particular, wildcards do not include directories contents
recursively. Furthermore, if a wildcard is used it must be used with
an extension, so `data-files: data/*` is not allowed. When matching
a wildcard plus extension, a file's full extension must match
exactly, so `*.gz` matches `foo.gz` but not `foo.tar.gz`. A wildcard
that does not match any files is an error.

The reason for providing only a very limited form of wildcard is to
concisely express the common case of a large number of related files
of the same file type without making it too easy to accidentally
include unwanted files.

data-dir: directory

The directory where Cabal looks for data files to install, relative to the source directory. By default, Cabal will look in the source directory itself.

extra-source-files: filename list

A list of additional files to be included in source distributions built with setup sdist. As with data-files it can use a limited form of * wildcards in file names.

extra-tmp-files: filename list

A list of additional files or directories to be removed by setup clean. These would typically be additional files created by additional hooks, such as the scheme described in the section on system-dependent parameters.

Library

The library section should contain the following fields:

exposed-modules: identifier list (required if this package contains a library)

A list of modules added by this package.

exposed: boolean (default: True)

Some Haskell compilers (notably GHC) support the notion of packages being “exposed” or “hidden” which means the modules they provide can be easily imported without always having to specify which package they come from. However this only works effectively if the modules provided by all exposed packages do not overlap (otherwise a module import would be ambiguous).

Almost all new libraries use hierarchical module names that do not
clash, so it is very uncommon to have to use this field. However it
may be necessary to set `exposed: False` for some old libraries that
use a flat module namespace or where it is known that the exposed
modules would clash with other common modules.

The library section may also contain build information fields (see the section on build information).

Executables

Executable sections (if present) describe executable programs contained in the package and must have an argument after the section label, which defines the name of the executable. This is a freeform argument but may not contain spaces.

The executable may be described using the following fields, as well as build information fields (see the section on build information).

main-is: filename (required)

The name of the .hs or .lhs file containing the Main module. Note that it is the .hs filename that must be listed, even if that file is generated using a preprocessor. The source file must be relative to one of the directories listed in hs-source-dirs.

Test suites

Test suite sections (if present) describe package test suites and must have an argument after the section label, which defines the name of the test suite. This is a freeform argument, but may not contain spaces. It should be unique among the names of the package’s other test suites, the package’s executables, and the package itself. Using test suite sections requires at least Cabal version 1.9.2.

The test suite may be described using the following fields, as well as build information fields (see the section on build information).

type: interface (required)

The interface type and version of the test suite. Cabal supports two test suite interfaces, called exitcode-stdio-1.0 and detailed-1.0. Each of these types may require or disallow other fields as described below.

Test suites using the exitcode-stdio-1.0 interface are executables that indicate test failure with a non-zero exit code when run; they may provide human-readable log information through the standard output and error channels. This interface is provided primarily for compatibility with existing test suites; it is preferred that new test suites be written for the detailed-1.0 interface. The exitcode-stdio-1.0 type requires the main-is field.

main-is: filename (required: exitcode-stdio-1.0, disallowed: detailed-1.0)

The name of the .hs or .lhs file containing the Main module. Note that it is the .hs filename that must be listed, even if that file is generated using a preprocessor. The source file must be relative to one of the directories listed in hs-source-dirs. This field is analogous to the main-is field of an executable section.

Test suites using the detailed-1.0 interface are modules exporting the symbol tests :: [Test]. The Test type is exported by the module Distribution.TestSuite provided by Cabal. For more details, see the example below.

The detailed-1.0 interface allows Cabal and other test agents to inspect a test suite’s results case by case, producing detailed human- and machine-readable log files. The detailed-1.0 interface requires the test-module field.

test-module: identifier (required: detailed-1.0, disallowed: exitcode-stdio-1.0)

The module exporting the tests symbol.

Name:           foo
Version:        1.0
License:        BSD3
Cabal-Version:  >= 1.9.2
Build-Type:     Simple

Test-Suite test-foo
    type:       exitcode-stdio-1.0
    main-is:    test-foo.hs
    build-depends: base

module Main where

import System.Exit (exitFailure)

main = do
    putStrLn "This test always fails!"
    exitFailure

Name:           bar
Version:        1.0
License:        BSD3
Cabal-Version:  >= 1.9.2
Build-Type:     Simple

Test-Suite test-bar
    type:       detailed-1.0
    test-module: Test.Bar
    build-depends: base, Cabal >= 1.9.2

{-# LANGUAGE FlexibleInstances #-}
module Test.Bar ( tests ) where

import Distribution.TestSuite

instance TestOptions (String, Bool) where
    name = fst
    options = const []
    defaultOptions _ = return (Options [])
    check _ _ = []

instance PureTestable (String, Bool) where
    run (name, result) _ | result == True = Pass
                         | result == False = Fail (name ++ " failed!")

test :: (String, Bool) -> Test
test = pure

-- In actual usage, the instances 'TestOptions (String, Bool)' and
-- 'PureTestable (String, Bool)', as well as the function 'test', would be
-- provided by the test framework.

tests :: [Test]
tests =
    [ test ("bar-1", True)
    , test ("bar-2", False)
    ]

Build information

The following fields may be optionally present in a library or executable section, and give information for the building of the corresponding library or executable. See also the sections on system-dependent parameters and configurations for a way to supply system-dependent values for these fields.

build-depends: package list

A list of packages needed to build this one. Each package can be annotated with a version constraint.

Version constraints use the operators `==, >=, >, <, <=` and a
version number. Multiple constraints can be combined using `&&` or
`||`. If no version constraint is specified, any version is assumed
to be acceptable. For example:

~~~~~~~~~~~~~~~~
library
  build-depends:
    base >= 2,
    foo >= 1.2 && < 1.3,
    bar
~~~~~~~~~~~~~~~~

Dependencies like `foo >= 1.2 && < 1.3` turn out to be very common
because it is recommended practise for package versions to
correspond to API versions. As of Cabal 1.6, there is a special
syntax to support this use:

~~~~~~~~~~~~~~~~
build-depends: foo ==1.2.*
~~~~~~~~~~~~~~~~

It is only syntactic sugar. It is exactly equivalent to `foo >= 1.2 && < 1.3`.

Note: Prior to Cabal 1.8, build-depends specified in each section
were global to all sections. This was unintentional, but some packages
were written to depend on it, so if you need your build-depends to
be local to each section, you must specify at least
`Cabal-Version: >= 1.8` in your `.cabal` file.

other-modules: identifier list

A list of modules used by the component but not exposed to users. For a library component, these would be hidden modules of the library. For an executable, these would be auxiliary modules to be linked with the file named in the main-is field.

Note: Every module in the package *must* be listed in one of
`other-modules`, `exposed-modules` or `main-is` fields.

hs-source-dirs: directory list (default: “.”)

Root directories for the module hierarchy.

For backwards compatibility, the old variant `hs-source-dir` is also
recognized.

extensions: identifier list

A list of Haskell extensions used by every module. Extension names are the constructors of the Extension type. These determine corresponding compiler options. In particular, CPP specifies that Haskell source files are to be preprocessed with a C preprocessor.

Extensions used only by one module may be specified by placing a
`LANGUAGE` pragma in the source file affected, e.g.:

~~~~~~~~~~~~~~~~
{-# LANGUAGE CPP, MultiParamTypeClasses #-}
~~~~~~~~~~~~~~~~

Note:  GHC versions prior to 6.6 do not support the `LANGUAGE` pragma.

build-tools: program list

A list of programs, possibly annotated with versions, needed to build this package, e.g. c2hs >= 0.15, cpphs.If no version constraint is specified, any version is assumed to be acceptable.

buildable: boolean (default: True)

Is the component buildable? Like some of the other fields below, this field is more useful with the slightly more elaborate form of the simple build infrastructure described in the section on system-dependent parameters.

ghc-options: token list

Additional options for GHC. You can often achieve the same effect using the extensions field, which is preferred.

Options required only by one module may be specified by placing an
`OPTIONS_GHC` pragma in the source file affected.

ghc-prof-options: token list

Additional options for GHC when the package is built with profiling enabled.

ghc-shared-options: token list

Additional options for GHC when the package is built as shared library.

hugs-options: token list

Additional options for Hugs. You can often achieve the same effect using the extensions field, which is preferred.

Options required only by one module may be specified by placing an
`OPTIONS_HUGS` pragma in the source file affected.

nhc98-options: token list

Additional options for nhc98. You can often achieve the same effect using the extensions field, which is preferred.

Options required only by one module may be specified by placing an
`OPTIONS_NHC98` pragma in the source file affected.

includes: filename list

A list of header files to be included in any compilations via C. This field applies to both header files that are already installed on the system and to those coming with the package to be installed. These files typically contain function prototypes for foreign imports used by the package.

install-includes: filename list

A list of header files from this package to be installed into $libdir/includes when the package is installed. Files listed in install-includes: should be found in relative to the top of the source tree or relative to one of the directories listed in include-dirs.

`install-includes` is typically used to name header files that
contain prototypes for foreign imports used in Haskell code in this
package, for which the C implementations are also provided with the
package.  Note that to include them when compiling the package
itself, they need to be listed in the `includes:` field as well.

include-dirs: directory list

A list of directories to search for header files, when preprocessing with c2hs, hsc2hs, ffihugs, cpphs or the C preprocessor, and also when compiling via C.

c-sources: filename list

A list of C source files to be compiled and linked with the Haskell files.

If you use this field, you should also name the C files in `CFILES`
pragmas in the Haskell source files that use them, e.g.: `{-# CFILES
dir/file1.c dir/file2.c #-}` These are ignored by the compilers, but
needed by Hugs.

extra-libraries: token list

A list of extra libraries to link with.

extra-lib-dirs: directory list

A list of directories to search for libraries.

cc-options: token list

Command-line arguments to be passed to the C compiler. Since the arguments are compiler-dependent, this field is more useful with the setup described in the section on system-dependent parameters.

ld-options: token list

Command-line arguments to be passed to the linker. Since the arguments are compiler-dependent, this field is more useful with the setup described in the section on system-dependent parameters>.

pkgconfig-depends: package list

A list of pkg-config packages, needed to build this package. They can be annotated with versions, e.g. gtk+-2.0 >= 2.10, cairo >= 1.0. If no version constraint is specified, any version is assumed to be acceptable. Cabal uses pkg-config to find if the packages are available on the system and to find the extra compilation and linker options needed to use the packages.

If you need to bind to a C library that supports `pkg-config` (use
`pkg-config --list-all` to find out if it is supported) then it is
much preferable to use this field rather than hard code options into
the other fields.

frameworks: token list

On Darwin/MacOS X, a list of frameworks to link to. See Apple’s developer documentation for more details on frameworks. This entry is ignored on all other platforms.

Configurations

Library and executable sections may include conditional blocks, which test for various system parameters and configuration flags. The flags mechanism is rather generic, but most of the time a flag represents certain feature, that can be switched on or off by the package user. Here is an example package description file using configurations:

Name: Test1
Version: 0.0.1
Cabal-Version: >= 1.2
License: BSD3
Author:  Jane Doe
Synopsis: Test package to test configurations
Category: Example

Flag Debug
  Description: Enable debug support
  Default:     False

Flag WebFrontend
  Description: Include API for web frontend.
  -- Cabal checks if the configuration is possible, first
  -- with this flag set to True and if not it tries with False

Library
  Build-Depends:   base
  Exposed-Modules: Testing.Test1
  Extensions:      CPP

  if flag(debug)
    GHC-Options: -DDEBUG
    if !os(windows)
      CC-Options: "-DDEBUG"
    else
      CC-Options: "-DNDEBUG"

  if flag(webfrontend)
    Build-Depends: cgi > 0.42
    Other-Modules: Testing.WebStuff

Executable test1
  Main-is: T1.hs
  Other-Modules: Testing.Test1
  Build-Depends: base

  if flag(debug)
    CC-Options: "-DDEBUG"
    GHC-Options: -DDEBUG

Name: Test1
Version: 0.0.1
Cabal-Version: >= 1.2
License: BSD3
Author:  Jane Doe
Synopsis: Test package to test configurations
Category: Example

Flag Debug {
  Description: Enable debug support
  Default:     False
}

Library {
  Build-Depends:   base
  Exposed-Modules: Testing.Test1
  Extensions:      CPP
  if flag(debug) {
    GHC-Options: -DDEBUG
    if !os(windows) {
      CC-Options: "-DDEBUG"
    } else {
      CC-Options: "-DNDEBUG"
    }
  }
}

Note that this value may be [overridden in several
ways](#controlling-flag-assignments"). The rationale for having
flags default to True is that users usually want new features as
soon as they are available. Flags representing features that are not
(yet) recommended for most users (such as experimental features or
debugging support) should therefore explicitly override the default
to False.

  `if `_condition_
       _property-descriptions-or-conditionals*_

  `if `_condition_
       _property-descriptions-or-conditionals*_
  `else`
       _property-descriptions-or-conditionals*_

Meaning of field values when using conditionals

During the configuration phase, a flag assignment is chosen, all conditionals are evaluated, and the package description is combined into a flat package descriptions. If the same field both inside a conditional and outside then they are combined using the following rules.

• Boolean fields are combined using conjunction (logical “and”).

• List fields are combined by appending the inner items to the outer items, for example

  Extensions: CPP
  if impl(ghc) || impl(hugs)
    Extensions: MultiParamTypeClasses
  

  when compiled using Hugs or GHC will be combined to

  Extensions: CPP, MultiParamTypeClasses
  

  Similarly, if two conditional sections appear at the same nesting level, properties specified in the latter will come after properties specified in the former.

• All other fields must not be specified in ambiguous ways. For example

  Main-is: Main.hs
  if flag(useothermain)
    Main-is: OtherMain.hs
  

  will lead to an error. Instead use

  if flag(useothermain)
    Main-is: OtherMain.hs
  else
    Main-is: Main.hs
  

Source Repositories

It is often useful to be able to specify a source revision control repository for a package. Cabal lets you specifying this information in a relatively structured form which enables other tools to interpret and make effective use of the information. For example the information should be sufficient for an automatic tool to checkout the sources.

Cabal supports specifying different information for various common source control systems. Obviously not all automated tools will support all source control systems.

Cabal supports specifying repositories for different use cases. By declaring which case we mean automated tools can be more useful. There are currently two kinds defined:

• The head kind refers to the latest development branch of the package. This may be used for example to track activity of a project or as an indication to outside developers what sources to get for making new contributions.

• The this kind refers to the branch and tag of a repository that contains the sources for this version or release of a package. For most source control systems this involves specifying a tag, id or hash of some form and perhaps a branch. The purpose is to be able to reconstruct the sources corresponding to a particular package version. This might be used to indicate what sources to get if someone needs to fix a bug in an older branch that is no longer an active head branch.

You can specify one kind or the other or both. As an example here are the repositories for the Cabal library. Note that the this kind of repo specifies a tag.

source-repository head
  type:     darcs
  location: http://darcs.haskell.org/cabal/

source-repository this
  type:     darcs
  location: http://darcs.haskell.org/cabal-branches/cabal-1.6/
  tag:      1.6.1

The exact fields are as follows:

type: token

The name of the source control system used for this repository. The currently recognised types are:

* `darcs`
* `git`
* `svn`
* `cvs`
* `mercurial` (or alias `hg`)
* `bazaar` (or alias `bzr`)
* `arch`
* `monotone`

This field is required.

location: URL

The location of the repository. The exact form of this field depends on the repository type. For example:

* for darcs: `http://code.haskell.org/foo/`
* for git: `git://github.com/foo/bar.git`
* for CVS: `anoncvs@cvs.foo.org:/cvs`

This field is required.

module: token

CVS requires a named module, as each CVS server can host multiple named repositories.

This field is required for the CVS repo type and should not be used
otherwise.

branch: token

Many source control systems support the notion of a branch, as a distinct concept from having repositories in separate locations. For example CVS, SVN and git use branches while for darcs uses different locations for different branches. If you need to specify a branch to identify a your repository then specify it in this field.

This field is optional.

tag: token

A tag identifies a particular state of a source repository. The tag can be used with a this repo kind to identify the state of a repo corresponding to a particular package version or release. The exact form of the tag depends on the repository type.

This field is required for the `this` repo kind.

subdir: directory

Some projects put the sources for multiple packages under a single source repository. This field lets you specify the relative path from the root of the repository to the top directory for the package, ie the directory containing the package’s .cabal file.

This field is optional. It default to empty which corresponds to the
root directory of the repository.

Example: Using autoconf

This example is for people familiar with the autoconf tools.

In the X11 package, the file configure.ac contains:

AC_INIT([Haskell X11 package], [1.1], [libraries@haskell.org], [X11])

# Safety check: Ensure that we are in the correct source directory.
AC_CONFIG_SRCDIR([X11.cabal])

# Header file to place defines in
AC_CONFIG_HEADERS([include/HsX11Config.h])

# Check for X11 include paths and libraries
AC_PATH_XTRA
AC_TRY_CPP([#include <X11/Xlib.h>],,[no_x=yes])

# Build the package if we found X11 stuff
if test "$no_x" = yes
then BUILD_PACKAGE_BOOL=False
else BUILD_PACKAGE_BOOL=True
fi
AC_SUBST([BUILD_PACKAGE_BOOL])

AC_CONFIG_FILES([X11.buildinfo])
AC_OUTPUT

Then the setup script will run the configure script, which checks for the presence of the X11 libraries and substitutes for variables in the file X11.buildinfo.in:

buildable: @BUILD_PACKAGE_BOOL@
cc-options: @X_CFLAGS@
ld-options: @X_LIBS@

This generates a file X11.buildinfo supplying the parameters needed by later stages:

buildable: True
cc-options:  -I/usr/X11R6/include
ld-options:  -L/usr/X11R6/lib

The configure script also generates a header file include/HsX11Config.h containing C preprocessor defines recording the results of various tests. This file may be included by C source files and preprocessed Haskell source files in the package.

Note: Packages using these features will also need to list additional files such as configure, templates for .buildinfo files, files named only in .buildinfo files, header files and so on in the extra-source-files field, to ensure that they are included in source distributions. They should also list files and directories generated by configure in the extra-tmp-files field to ensure that they are removed by setup clean.

Programs used for building

The following options govern the programs used to process the source files of a package:

--ghc or -g, --nhc, --jhc, --hugs

Specify which Haskell implementation to use to build the package. At most one of these flags may be given. If none is given, the implementation under which the setup script was compiled or interpreted is used.

--with-compiler=path or -wpath

Specify the path to a particular compiler. If given, this must match the implementation selected above. The default is to search for the usual name of the selected implementation.

This flag also sets the default value of the `--with-hc-pkg` option
to the package tool for this compiler. Check the output of `setup
configure -v` to ensure that it finds the right package tool (or use
`--with-hc-pkg` explicitly).

--with-hc-pkg=path

Specify the path to the package tool, e.g. ghc-pkg. The package tool must be compatible with the compiler specified by --with-compiler. If this option is omitted, the default value is determined from the compiler selected.

--with-prog=path

Specify the path to the program prog. Any program known to Cabal can be used in place of prog. It can either be a fully path or the name of a program that can be found on the program search path. For example: --with-ghc=ghc-6.6.1 or --with-cpphs=/usr/local/bin/cpphs.

--prog-options=options

Specify additional options to the program prog. Any program known to Cabal can be used in place of prog. For example: --alex-options="--template=mytemplatedir/". The options is split into program options based on spaces. Any options containing embeded spaced need to be quoted, for example --foo-options='--bar="C:\Program File\Bar"'. As an alternative that takes only one option at a time but avoids the need to quote, use --prog-option instead.

--prog-option=option

Specify a single additional option to the program prog. For passing an option that contain embeded spaces, such as a file name with embeded spaces, using this rather than --prog-options means you do not need an additional level of quoting. Of course if you are using a command shell you may still need to quote, for example --foo-options="--bar=C:\Program File\Bar".

All of the options passed with either --prog-options or --prog-option are passed in the order they were specified on the configure command line.

Installation paths

The following options govern the location of installed files from a package:

--prefix=dir

The root of the installation. For example for a global install you might use /usr/local on a Unix system, or C:\Program Files on a Windows system. The other installation paths are usually subdirectories of prefix, but they don’t have to be.

In the simple build system, _dir_ may contain the following path
variables: `$pkgid`, `$pkg`, `$version`, `$compiler`, `$os`,
`$arch`

--bindir=dir

Executables that the user might invoke are installed here.

In the simple build system, _dir_ may contain the following path
variables: `$prefix`, `$pkgid`, `$pkg`, `$version`, `$compiler`,
`$os`, `$arch`

--libdir=dir

Object-code libraries are installed here.

In the simple build system, _dir_ may contain the following path
variables: `$prefix`, `$bindir`, `$pkgid`, `$pkg`, `$version`,
`$compiler`, `$os`, `$arch`

--libexecdir=dir

Executables that are not expected to be invoked directly by the user are installed here.

In the simple build system, _dir_ may contain the following path
variables: `$prefix`, `$bindir`, `$libdir`, `$libsubdir`, `$pkgid`,
`$pkg`, `$version`, `$compiler`, `$os`, `$arch`

--datadir=dir

Architecture-independent data files are installed here.

In the simple build system, _dir_ may contain the following path
variables: `$prefix`, `$bindir`, `$libdir`, `$libsubdir`, `$pkgid`, `$pkg`,
`$version`, `$compiler`, `$os`, `$arch`

In addition the simple build system supports the following installation path options:

--libsubdir=dir

A subdirectory of libdir in which libraries are actually installed. For example, in the simple build system on Unix, the default libdir is /usr/local/lib, and libsubdir contains the package identifier and compiler, e.g. mypkg-0.2/ghc-6.4, so libraries would be installed in /usr/local/lib/mypkg-0.2/ghc-6.4.

_dir_ may contain the following path variables: `$pkgid`, `$pkg`,
`$version`, `$compiler`, `$os`, `$arch`

--datasubdir=dir

A subdirectory of datadir in which data files are actually installed.

_dir_ may contain the following path variables: `$pkgid`, `$pkg`,
`$version`, `$compiler`, `$os`, `$arch`

--docdir=dir

Documentation files are installed relative to this directory.

_dir_ may contain the following path variables: `$prefix`, `$bindir`,
`$libdir`, `$libsubdir`, `$datadir`, `$datasubdir`, `$pkgid`, `$pkg`,
`$version`, `$compiler`, `$os`, `$arch`

--htmldir=dir

HTML documentation files are installed relative to this directory.

_dir_ may contain the following path variables: `$prefix`, `$bindir`,
`$libdir`, `$libsubdir`, `$datadir`, `$datasubdir`, `$docdir`, `$pkgid`,
`$pkg`, `$version`, `$compiler`, `$os`, `$arch`

--program-prefix=prefix

Prepend prefix to installed program names.

_prefix_ may contain the following path variables: `$pkgid`, `$pkg`,
`$version`, `$compiler`, `$os`, `$arch`

--program-suffix=suffix

Append suffix to installed program names. The most obvious use for this is to append the program’s version number to make it possible to install several versions of a program at once: --program-suffix='$version'.

_suffix_ may contain the following path variables: `$pkgid`, `$pkg`,
`$version`, `$compiler`, `$os`, `$arch`

Controlling Flag Assignments

Flag assignments (see the resolution of conditions and flags) can be controlled with the followingcommand line options.

-f flagname or -f -flagname

Force the specified flag to true or false (if preceded with a -). Later specifications for the same flags will override earlier, i.e., specifying -fdebug -f-debug is equivalent to -f-debug

--flags=flagspecs

Same as -f, but allows specifying multiple flag assignments at once. The parameter is a space-separated list of flag names (to force a flag to true), optionally preceded by a - (to force a flag to false). For example, --flags="debug -feature1 feature2" is equivalent to -fdebug -f-feature1 -ffeature2.

Building Test Suites

--enable-tests

Build the test suites defined in the package description file during the build stage. Check for dependencies required by the test suites. If the package is configured with this option, it will be possible to run the test suites with the test command after the package is built.

--disable-tests

(default) Do not build any test suites during the build stage. Do not check for dependencies required only by the test suites. It will not be possible to invoke the test command without reconfiguring the package.

Miscellaneous options

--user

Does a per-user installation. This changes the default installation prefix. It also allow dependencies to be satisfied by the user’s package database, in addition to the global database. This also implies a default of --user for any subsequent install command, as packages registered in the global database should not depend on packages registered in a user’s database.

--global

(default) Does a global installation. In this case package dependencies must be satisfied by the global package database. All packages in the user’s package database will be ignored. Typically the final instllation step will require administrative privileges.

--package-db=db

Allows package dependencies to be satisfied from this additional package database db in addition to the global package database. All packages in the user’s package database will be ignored. The interpretation of db is implementation-specific. Typically it will be a file or directory. Not all implementations support arbitrary package databases.

--enable-optimization[=n] or -O[n]

(default) Build with optimization flags (if available). This is appropriate for production use, taking more time to build faster libraries and programs.

The optional _n_ value is the optimisation level. Some compilers
support multiple optimisation levels. The range is 0 to 2. Level 0
is equivalent to `--disable-optimization`, level 1 is the default if
no _n_ parameter is given. Level 2 is higher optimisation if the
compiler supports it. Level 2 is likely to lead to longer compile
times and bigger generated code.

--disable-optimization

Build without optimization. This is suited for development: building will be quicker, but the resulting library or programs will be slower.

--enable-library-profiling or -p

Request that an additional version of the library with profiling features enabled be built and installed (only for implementations that support profiling).

--disable-library-profiling

(default) Do not generate an additional profiling version of the library.

--enable-executable-profiling

Any executables generated should have profiling enabled (only for implementations that support profiling). For this to work, all libraries used by these executables must also have been built with profiling support.

--disable-executable-profiling

(default) Do not enable profiling in generated executables.

--enable-library-vanilla

(default) Build ordinary libraries (as opposed to profiling libraries). This is independent of the --enable-library-profiling option. If you enable both, you get both.

--disable-library-vanilla

Do not build ordinary libraries. This is useful in conjunction with --enable-library-profiling to build only profiling libraries, rather than profiling and ordinary libraries.

--enable-library-for-ghci

(default) Build libraries suitable for use with GHCi.

--disable-library-for-ghci

Not all platforms support GHCi and indeed on some platforms, trying to build GHCi libs fails. In such cases this flag can be used as a workaround.

--enable-split-objs

Use the GHC -split-objs feature when building the library. This reduces the final size of the executables that use the library by allowing them to link with only the bits that they use rather than the entire library. The downside is that building the library takes longer and uses considerably more memory.

--disable-split-objs

(default) Do not use the GHC -split-objs feature. This makes building the library quicker but the final executables that use the library will be larger.

--enable-executable-stripping

(default) When installing binary executable programs, run the strip program on the binary. This can considerably reduce the size of the executable binary file. It does this by removing debugging information and symbols. While such extra information is useful for debugging C programs with traditional debuggers it is rarely helpful for debugging binaries produced by Haskell compilers.

Not all Haskell implementations generate native binaries. For such
implementations this option has no effect.

--disable-executable-stripping

Do not strip binary executables during installation. You might want to use this option if you need to debug a program using gdb, for example if you want to debug the C parts of a program containing both Haskell and C code. Another reason is if your are building a package for a system which has a policy of managing the stripping itself (such as some linux distributions).

--enable-shared

Build shared library. This implies a seperate compiler run to generate position independent code as required on most platforms.

--disable-shared

(default) Do not build shared library.

--configure-option=str

An extra option to an external configure script, if one is used (see the section on system-dependent parameters). There can be several of these options.

--extra-include-dirs[=dir]

An extra directory to search for C header files. You can use this flag multiple times to get a list of directories.

You might need to use this flag if you have standard system header
files in a non-standard location that is not mentioned in the
package's `.cabal` file. Using this option has the same affect as
appending the directory _dir_ to the `include-dirs` field in each
library and executable in the package's `.cabal` file. The advantage
of course is that you do not have to modify the package at all.
These extra directories will be used while building the package and
for libraries it is also saved in the package registration
information and used when compiling modules that use the library.

--extra-lib-dirs[=dir]

An extra directory to search for system libraries files. You can use this flag multiple times to get a list of directories.

You might need to use this flag if you have standard system
libraries in a non-standard location that is not mentioned in the
package's `.cabal` file. Using this option has the same affect as
appending the directory _dir_ to the `extra-lib-dirs` field in each
library and executable in the package's `.cabal` file. The advantage
of course is that you do not have to modify the package at all.
These extra directories will be used while building the package and
for libraries it is also saved in the package registration
information and used when compiling modules that use the library.

In the simple build infrastructure, an additional option is recognized:

--scratchdir=dir

Specify the directory into which the Hugs output will be placed (default: dist/scratch).

Very Stable Command-line interfaces

• ./setup configure
• --prefix
• --user
• --ghc, --hugs
• --verbose

• --prefix

• ./setup build
• ./setup install
• ./setup register

• ./setup copy

Stable Command-line interfaces

Unstable command-line

Very Stable API

• defaultMain

• defaultMainWithHooks defaultUserHooks

But regular defaultMainWithHooks isn’t stable since UserHooks changes.

Semi-stable API

• UserHooks The hooks API will change in the future

• Distribution.* is mostly declarative information about packages and is somewhat stable.

Unstable API

Everything under Distribution.Simple.* has no stability guarantee.