Search code, repositories, users, issues, pull requests...

Default: []

Packages which, when present in the snapshot specified in the snapshot or resolver key, should not be included in our project. This can be used for a few different purposes, e.g.:

Ensure that packages you don't want used in your project cannot be used in a package.yaml file (e.g., for license reasons)
When using a custom GHC build, avoid incompatible packages (see this comment).

drop-packages:
- buggy-package
- package-with-unacceptable-license

!!! info

Stackage snapshots LTS Haskell 14.27 (GHC 8.6.5) and earlier, and Nightly
2022-02-08 (GHC 8.8.2) and earlier, included directly the `Cabal` package.
Later snapshots do not include directly that package (which is a GHC boot
package).

For the older Stackage snapshots, it could be handy to drop the
snapshot-specified `Cabal` package, to avoid building that version of the
package. For the later snapshots, there is no package version to drop.

user-message

If present, specifies a message to be displayed every time the configuration is loaded by Stack. It can serve as a reminder for the user to review the configuration and make any changes if needed. The user can delete this message if the generated configuration is acceptable.

For example, a user-message is inserted by stack init when it omits packages or adds external dependencies, namely:

user-message: ! 'Warning: Some packages were found to be incompatible with the snapshot
  and have been left commented out in the packages section.

  Warning: Specified snapshot could not satisfy all dependencies. Some external packages
  have been added as dependencies.

  You can omit this message by removing it from stack.yaml

'

custom-preprocessor-extensions

Default: []

Command line equivalent: --customer-preprocessor-extensions option

In order for Stack to be aware of any custom preprocessors you are using, add their extensions here

custom-preprocessor-extensions:
- erb

TODO: Add a simple example of how to use custom preprocessors.

extra-package-dbs

:octicons-tag-24: 2.1.0.1

Default: []

A list of relative or absolute paths to package databases. These databases will be added on top of GHC's global package database before the addition of other package databases.

!!! warning

Use of this feature may result in builds that are not reproducible, as Stack
has no control over the contents of the extra package databases.

curator

:octicons-beaker-24: Experimental

Default: {}

Configuration intended for use only by the curator tool, which uses Stack to build packages. For given package names (which need not exist in the project), Stack can be configured to ignore (skip) silently building test suites, building benchmarks and/or creating Haddock documentation or to expect that building test suites, building benchmarks and/or creating Haddock documentation will fail.

For example:

curator:
  skip-test:
  - my-package1
  expect-test-failure:
  - my-package2
  skip-bench:
  - my-package3
  expect-benchmark-failure:
  - my-package4
  skip-haddock:
  - my-package5
  expect-haddock-failure:
  - my-package6

Non-project-specific configuration

Non-project configuration options can be included in a project-level configuration file (stack.yaml, by default) or in global configuration files (config.yaml). However, non-project-specific options in the project-level configuration file in the global-project directory are ignored by Stack. The options below are listed in alphabetic order.

allow-different-user

:octicons-tag-24: 1.0.1.0

Restrictions: POSIX systems only.

Default: false

Command line equivalent (takes precedence): --[no-]allow-different-user flag

Allow users other than the owner of the Stack root to use the Stack installation.

allow-different-user: true

The intention of this option is to prevent file permission problems, for example as the result of a Stack command executed under sudo.

The option is automatically enabled when Stack is re-spawned in a Docker process.

allow-newer

:octicons-tag-24: 0.1.8.0

Default: false

Command line equivalent (takes precedence): stack build --[no-]allow-newer flag

Whether to ignore lower and upper version bounds in Cabal files.

!!! info

The name `allow-newer` was chosen to match a commonly-used Cabal option
which ignored only upper bounds.

allow-newer: true

allow-newer-deps

:octicons-beaker-24: Experimental

:octicons-tag-24: 2.9.3

Default: none

Determines a subset of packages to which allow-newer should apply. This option has no effect (but warns) if allow-newer is false.

allow-newer-deps:
  - foo
  - bar

apply-ghc-options

:octicons-tag-24: 0.1.8.0

Default: locals

Related command line: stack build --ghc-options option

Determines to which packages any GHC command line options specified on the command line are applied. Possible values are: everything (all packages, project packages or otherwise), locals (all project packages, targets or otherwise), and targets (all project packages that are targets).

!!! note

The use of `everything` can break invariants about your snapshot database.

!!! info

Before Stack 0.1.6.0, the default value was `targets`.

apply-prog-options

:octicons-tag-24: 2.11.1

Default: locals

Related command line: stack build --PROG-option options

Determines to which packages all and any --PROG-option command line options specified on the command line are applied. Possible values are: everything (all packages, project packages or otherwise), locals (all project packages, targets or otherwise), and targets (all project packages that are targets).

!!! note

The use of `everything` can break invariants about your snapshot database.

arch

Default: The machine architecture on which Stack is running.

Command line equivalent (takes precedence): --arch option

Stack identifies different GHC executables by platform (operating system and machine architecture), (optional) GHC variant and (optional) GHC build. See setup-info.

arch sets the machine architecture. Values can be those recognized by Cabal (the library) (which are case-insensitive and include i386, x86_64, and aarch64 / arm64), or other values (which are case-sensitive and treated as an unknown 'other' architecture of the specified name).

By default, Stack will warn the user if the specified machine architecture is an unknown 'other' architecture. The warning can be muted; see notify-if-arch-unknown

!!! note

The machine architecture on which Stack is running is as classified by
Cabal (the library). Cabal does not distinguish between certain
architectures. Examples are `ppc64`/`powerpc64`/`powerpc64le` (classified as
`ppc64`) and `arm`/`armel`/`armeb` (classified as `arm`).

!!! note

As Cabal (the library) does not distinguish between machine architectures
`powerpc64` and `powerpc64le`, the latter can be specified in Stack's
configuration as an 'other' architecture, such as `arch: ppc64le`.

build

:octicons-tag-24: 1.1.0

Default:

build:
  library-profiling: false
  executable-profiling: false
  library-stripping: true
  executable-stripping: true

  # NOTE: global usage of haddock can cause build failures when documentation is
  # incorrectly formatted. This could also affect scripts which use Stack.
  haddock: false
  haddock-arguments:

    # Additional arguments passed to haddock. The corresponding command line
    # option is --haddock-arguments. Example of use:
    #
    # haddock-args:
    # - "--css=/home/user/my-css"
    haddock-args: []

  # The corresponding command line flag is --[no-]open.
  open-haddocks: false

  # If Stack is configured to build Haddock documentation, defaults to true.
  haddock-deps: false

  # The configuration is ignored, if haddock-for-hackage: true.
  haddock-internal: false

  # The configuration is ignored, if haddock-for-hackage: true.
  haddock-hyperlink-source: true

  # If specified, implies haddock-internal: false and
  # haddock-hyperlink-source: true. Since Stack 2.15.1.
  haddock-for-hackage: false
  copy-bins: false
  copy-compiler-tool: false
  prefetch: false
  keep-going: false
  keep-tmp-files: false

  # These are inadvisable to use in your global configuration, as they make the
  # Stack build command line behave quite differently.
  force-dirty: false
  test: false
  test-arguments:
    rerun-tests: true   # Rerun successful tests

    # The corresponding command line option is --test-arguments. Example of use:
    #
    # additional-args:
    # - "--fail-fast"
    additional-args: []
    coverage: false
    no-run-tests: false
  bench: false
  benchmark-opts:

    # Example of use:
    #
    # benchmark-arguments: "--csv bench.csv"
    benchmark-arguments: ""
    no-run-benchmarks: false
  reconfigure: false
  cabal-verbosity: normal
  cabal-verbose: false
  split-objs: false
  skip-components: [] # --skip

  # Since Stack 1.8. Starting with Stack 2.0, the default is true
  interleaved-output: true

  # Since Stack 2.13.1. Available options are none, count-only, capped and full.
  progress-bar: capped

  # Since Stack 1.10.
  ddump-dir: ""

Command line equivalents (take precedence): Yes, see below.

Allows setting build options which are usually specified on the command line.

The meanings of these settings correspond directly with the command line flags of the same name. For further information, see the stack build command documentation and the users guide.

casa

:octicons-tag-24: 2.13.1

Default:

casa:
  enable: true # Use a Casa server?
  repo-prefix: https://casa.stackage.org # Unless casa-repo-prefix is set.
  max-keys-per-request: 1280 # Maximum number of keys per request.

This option specifies whether or not Stack should use a Casa (content-addressable storage archive) server to cache Cabal files and all other files in packages; and, if so, the prefix for the URL used to pull information from the server and the maximum number of keys per request. For further information, see this blog post about Casa and Stack.

repo-prefix replaces casa-repo-prefix (which is deprecated) and has precedence if both keys are set.

casa-repo-prefix

:octicons-tag-24: 2.3.1

Deprecated in favour of casa, which takes precedence if present.

Default: https://casa.stackage.org

This option specifies the prefix for the URL used to pull information from the Casa server.

color

Command line equivalent (takes precedence): --color option

This option specifies when to use color in output. The option is used as color: <WHEN>, where <WHEN> is 'always', 'never', or 'auto'. On Windows versions before Windows 10, for terminals that do not support color codes, the default is 'never'; color may work on terminals that support color codes.

(The British English spelling (colour) is also accepted. In yaml configuration files, the American spelling is the alternative that has priority.)

compiler

Command line equivalent (takes precedence): --compiler option

Overrides the compiler version in the snapshot. Note that the compiler-check flag also applies to the version numbers. This uses the same syntax as compiler snapshots like ghc-9.6.6. This can be used to override the compiler for a Stackage snapshot, like this:

snapshot: lts-22.28
compiler: ghc-9.6.5
compiler-check: match-exact

Building GHC from source

:octicons-beaker-24: Experimental

:octicons-tag-24: 0.1.4.0

Stack supports building the GHC compiler from source, using Hadrian (the build system for GHC). The GHC version to build and to use is defined by a a Git commit ID and a Hadrian "flavour", with the following syntax:

compiler: ghc-git-<commit_id>-<Hadrian_flavour>

In the following example the commit ID is "5be7ad..." and the flavour is "quick":

compiler: ghc-git-5be7ad7861c8d39f60b7101fd8d8e816ff50353a-quick

By default, the code is retrieved from the main GHC repository. If you want to select another repository, use the compiler-repository option:

compiler-repository: git://my/ghc/repository
# default
# compiler-repository: https://gitlab.haskell.org/ghc/ghc.git

Stack does not check the compiler version when it uses a compiler built from source. It is assumed that the built compiler is recent enough as Stack doesn't enable any known workaround to make older compilers work.

Building the compiler can take a very long time (more than one hour). For faster build times, use Hadrian flavours that disable documentation generation.

Bootstrap compiler

Building GHC from source requires a working GHC (known as the bootstrap compiler). As we use a Stack based version of Hadrian (hadrian/build-stack in GHC sources), the bootstrap compiler is configured into hadrian/stack.yaml and fully managed by Stack.

!!! note

For some commit IDs, the snapshot specified in `hadrian/stack.yaml`
specifies a version of GHC that cannot be used to build GHC. This results in
GHC's `configure` script reporting messages similar to the following before
aborting:

~~~text
checking version of ghc... 9.0.2
configure: error: GHC version 9.2 or later is required to compile GHC.
~~~

The resolution is: (1) to specify an alternative snapshot (one that
specifies a sufficiently recent version of GHC) on the command line, using
Stack's option `--snapshot <snapshot>`. Stack will use that snapshot when
running GHC's `configure` script; and (2) to set the contents of the `STACK`
environment variable to be `stack --snapshot <snapshot>`. Hadrian's
`build-stack` script wil refer to that environment variable for the Stack
command it uses.

Hadrian prerequisites

The Hadrian build system has certain prerequisites. It requires certain versions of the happy and alex executables on the PATH. Stack will build and install happy and alex, if not already on the PATH.

=== "macOS"

Hadrian requires, or case use, certain tools or Python packages that do not
come with macOS by default and that need to be installed using `brew` or
`pip3` (Python). Hadrian's LaTeX documentation also requires the
[DejaVu fonts](https://dejavu-fonts.github.io/) to be installed.

~~~zsh
brew install python@3.11
# GHC uses a Python script named `boot`.
brew install automake
# Tool for generating GNU Standards-compliant Makefiles.
brew install texinfo
# Official documentation format of the GNU project.
pip3 install -U sphinx
# Sphinx is the Python documentation generator.
brew install --cask mactex
# MacTeX: Full TeX Live distribution with GUI applications
~~~

=== "Windows"

Hadrian requires, or can use, certain MSYS2 or Python packages that do not
come with the Stack-supplied MSYS2 by default and need to be installed
using `pacman` (MSYS2) or `pip` (Python). Hadrian's LaTeX documentation also
requires the [DejaVu fonts](https://dejavu-fonts.github.io/) to be
installed.

~~~pwsh
stack exec -- pacman --sync --refresh
# Synchronize MSYS2 package databases
stack exec -- pacman --sync mingw-w64-x86_64-python-pip
# The PyPA recommended tool (pip) for installing Python packages. Also
# installs Python as a dependency. GHC uses a Python script named `boot`.
# The package must be the one from the `mingw64` MSYS2 repository, as Python
# from the `msys` repository cannot interpret Windows file paths correctly.
stack exec -- pacman --sync mingw-w64-x86_64-autotools
# The GNU autotools build system, including `autoreconf`, `aclocal`
# and `make`. GHC uses a sh script named `configure` which is itself created
# from a file named `configure.ac`.
stack exec -- pacman --sync patch
# A utility to apply patch files to original sources.
stack exec -- pacman --sync texinfo
# Utilities to work with and produce manuals, ASCII text, and on-line
# documentation from a single source file, including `makeinfo`.
stack exec -- pacman --sync mingw-w64-x86_64-ca-certificates
# Common CA (certificate authority) certificates.
stack exec -- pip install -U sphinx
# Sphinx is the Python documentation generator.
~~~

Hadrian may require certain LaTeX packages and may prompt for these to be
installed duing the build process.

Global packages

The GHC compiler you build from sources may depend on unreleased versions of some global packages (e.g. Cabal). It may be an issue if a package you try to build with this compiler depends on such global packages because Stack may not be able to find versions of those packages (on Hackage, etc.) that are compatible with the compiler.

The easiest way to deal with this issue is to drop the offending packages as follows. Instead of using the packages specified in the snapshot, the global packages bundled with GHC will be used.

drop-packages:
- Cabal
- ...

Another way to deal with this issue is to add the relevant packages as extra-deps built from source. To avoid mismatching versions, you can use exactly the same commit id you used to build GHC as follows:

extra-deps:
- git: https://gitlab.haskell.org/ghc/ghc.git
  commit: '5be7ad7861c8d39f60b7101fd8d8e816ff50353a'
  subdirs:
    - libraries/Cabal/Cabal
    - libraries/...

compiler-check

Default: match-minor

Specifies how the compiler version in the snapshot is matched against concrete versions. Valid values:

match-minor: make sure that the first three components match, but allow patch-level differences. For example< 7.8.4.1 and 7.8.4.2 would both match 7.8.4. This is useful to allow for custom patch levels of a compiler.
match-exact: the entire version number must match precisely
newer-minor: the third component can be increased, e.g. if your snapshot is ghc-7.10.1, then 7.10.2 will also be allowed. This was the default up through Stack 0.1.3

concurrent-tests

:octicons-tag-24: 0.1.2.0

Default: true

This option specifies whether test suites should be executed concurrently with each other. The default is true since this is usually fine and it often means that tests can complete earlier. However, if some test suites require exclusive access to some resource, or require a great deal of CPU or memory resources, then it makes sense to set this to false.

concurrent-tests: false

configure-options

:octicons-tag-24: 0.1.4.0

Related command line (takes precedence): stack build --PROG-option options

configure-options can specify Cabal (the library) options (including --PROG-option or --PROG-options options) for the configure step of the Cabal build process for a named package, all project packages that are targets (using the $targets key), all project packages (targets or otherwise) (using the $locals key), or all packages (project packages or otherwise) (using the $everything key).

configure-options:
  $everything:
  - --with-gcc
  - /some/path
  $locals:
  - --happy-option=--ghc
  $targets:
  # Only works on platforms where GHC supports linking against shared Haskell
  # libraries:
  - --enable-executable-dynamic
  my-package:
  - --another-flag

On platforms where GHC supports linking against shared Haskell libraries (that currently excludes Windows), Cabal's --enable-executable-dynamic flag (which implies --enable-shared, unless --disable-shared is specified) links dependent Haskell libraries into executables dynamically.

connection-count

Default: 8

Integer indicating how many simultaneous downloads are allowed to happen.

default-init-snapshot

:octicons-tag-24: UNRELEASED

Default: As for the stack init command when no snapshot is specified at the command line.

Command line equivalent (takes precedence): --snapshot or --resolver option

This option specifies which snapshot to use with stack init, when none is specified at the command line.

default-init-snapshot: global specifies the snapshot specified by the project-level configuration file in the global-project directory in the Stack root.

default-template

Default: new-template in the stack-templates repository.

This option specifies which template to use with stack new, when none is specified. Other templates are listed in the stack-templates repository. See the output of stack templates.

docker

Command line equivalents: --docker-* flags and options (see stack --docker-help for details).

For further information, see the Docker integration documentation.

dump-logs

:octicons-tag-24: 1.3.0

Default: warning

Command line equivalent (takes precedence): --[no-]dump-logs flag

In the case of non-interleaved output and more than one target package, Stack sends the build output from GHC for each target package to a log file, unless an error occurs that prevents that. For further information, see the stack build --[no-]interleaved-output flag documentation.

The value of the dump-logs key controls what, if any, log file content is sent ('dumped') to the standard error stream of the console at the end of the build. Possible values are:

dump-logs: none    # don't dump the content of any log files
dump-logs: warning # dump the content of any log files that include GHC warnings
dump-logs: all     # dump the content of all log files

At the command line, --no-dump-logs is equivalent to dump-logs: none and --dump-logs is equivalent to dump-logs: all.

If GHC reports an error during the build and a log file is created, that build output will be included in the log file. Stack will also report errors during building to the standard error stream. That stream can be piped to a file. For example, for a file named stderr.log:

stack --no-dump-logs --color always build --no-interleaved-output 2> stderr.log

extra-include-dirs

Default: []

Command line equivalent: --extra-include-dirs option (repeat for each directory)

A list of extra paths to be searched for header files. Paths should be absolute

extra-include-dirs:
- /opt/foo/include

Since these are system-dependent absolute paths, it is recommended that you specify these in your config.yaml file. If you control the build environment in your project's stack.yaml, perhaps through docker or other means, then it may well make sense to include these there as well.

extra-lib-dirs

Default: []

Command line equivalent: --extra-lib-dirs option (repeat for each directory)

A list of extra paths to be searched for libraries. Paths should be absolute

extra-lib-dirs:
- /opt/foo/lib

Since these are system-dependent absolute paths, it is recommended that you specify these in your config.yaml file. If you control the build environment in your project's stack.yaml, perhaps through Docker or other means, then it may well make sense to include these there as well.

extra-path

This option specifies additional directories to prepend to the PATH. These will be used when resolving the location of executables, and will also be visible in the PATH of processes run by Stack.

For example, to prepend /path-to-some-dep/bin to your PATH:

extra-path:
- /path-to-some-dep/bin

Other paths added by Stack - things like the project's binary directory and the compiler's binary directory - will take precedence over those specified here (the automatic paths get prepended).

file-watch-hook

:octicons-tag-24: UNRELEASED

Specifies the location of an executable or sh shell script to be run after each attempted build with build --file-watch. An absolute or relative path can be specified. Changes to the configuration after the initial build --file-watch command are ignored.

If the project-level configuration is provided in the global-project directory in the Stack root, a relative path is assumed to be relative to the current directory. Otherwise, it is assumed to be relative to the directory of the project-level configuration file.

ghc-build

:octicons-tag-24: 1.3.0

Default: standard

Command line equivalent (takes precedence): --ghc-build option

Stack identifies different GHC executables by platform (operating system and machine architecture), (optional) GHC variant and (optional) GHC build. See setup-info.

ghc-build specifies a specialized architecture for the GHC executable. Normally this is determined automatically, but it can be overridden. Possible arguments include standard, gmp4, nopie, tinfo6, tinfo6-libc6-pre232, tinfo6-nopie, ncurses6, int-native and integersimple.

ghc-options

:octicons-tag-24: 0.1.4.0

Default: {}

Related command line (takes precedence): stack build --ghc-options option

GHC command line options can be specified for a package in its Cabal file (including one created from a package.yaml file). This option augments and, if applicable (see below), overrides any such GHC command line options.

ghc-options can specify GHC command line options for a named package, all project packages that are targets (using the $targets key), all project packages (targets or otherwise) (using the $locals key), or all packages (project packages or otherwise) (using the $everything key).

ghc-options:
  "$everything": -O2
  "$locals": -Wall
  "$targets": -Werror
  some-package: -DSOME_CPP_FLAG

GHC's command line options are order-dependent and evaluated from left to right. Later options can override the effect of earlier ones. Stack applies options (as applicable) in the order of $everything, $locals, $targets, and then those for the named package. Any GHC command line options for a package specified at Stack's command line are applied after those specified in Stack's YAML configuration files.

Since Stack 1.6.1, setting a GHC options for a specific package will automatically promote it to a project package (much like setting a custom package flag). However, setting options via $everything on all flags will not do so (see GitHub discussion for reasoning). This can lead to unpredictable behavior by affecting your snapshot packages.

!!! info

Before Stack 1.6.1, the key `*` (then deprecated) had the same function as
the key `$everything`.

ghc-variant

:octicons-tag-24: 0.1.5.0

Default: standard

Command line equivalent (takes precedence): --ghc-variant option

Stack identifies different GHC executables by platform (operating system and machine architecture), (optional) GHC variant and (optional) GHC build. See setup-info.

ghc-variant specifies a variant of the GHC executable. Known values are:

standard: Use the standard GHC binary distribution
int-native: From GHC 9.4.1, use a GHC bindist that uses the Haskell-native big-integer backend. For further information, see this article.
integersimple: Use a GHC bindist that uses integer-simple instead of GMP
any other value: Use a custom GHC bindist. You should specify setup-info or setup-info-locations so stack setup knows where to download it, or pass the stack setup --ghc-bindist argument on the command-line

This option is incompatible with system-ghc: true.

global-hints-location

:octicons-tag-24: UNRELEASED

Default:

global-hints-location:
  url: https://raw.githubusercontent.com/commercialhaskell/stackage-content/master/stack/global-hints.yaml

(as set in the pantry library)

Sets the location of the global hints YAML file. The location can be either a filepath of a local file or a URL. The filepath can be absolute or relative to the Stack root.

For example:

global-hints-location:
  filepath: \pantry\global-hints.yaml

or:

global-hints-location:
  url: https://example.com/global-hints/location/global-hints.yaml

hackage-base-url

:octicons-tag-24: 1.9.1

Default: https://hackage.haskell.org/

Sets the address of the Hackage server to upload the package to.

hackage-base-url: https://hackage.example.com/

hide-source-paths

Default: true (:octicons-tag-24: 2.1.1)

Whether to use the -fhide-source-paths option by default for GHC >= 8.2:

hide-source-paths: false

Build output when enabled:

...
[1 of 2] Compiling Lib
[2 of 2] Compiling Paths_test_pr
...

Build output when disabled:

...
[1 of 2] Compiling Lib              ( src/Lib.hs, .stack-work/dist/x86_64-linux-tinfo6/Cabal-2.4.0.1/build/Lib.o )
...

hide-th-loading

Default: true

Strip out the "Loading ..." lines from GHC build output, produced when using Template Haskell.

hpack-force

:octicons-tag-24: UNRELEASED

Default: false

Command line equivalent (takes precedence): --hpack-force option

Whether or not to allow Hpack to overwrite a Cabal file that has been modified manually. By default, Hpack 0.20.0 or later will decline to overwrite such a Cabal file.

ignore-revision-mismatch

(Removed 1.11)

This flag was introduced in Stack 1.6, and removed on the move to Pantry. You will receive a warning if this configuration value is set.

install-ghc

Default: true (:octicons-tag-24: 1.5.0)

Command line equivalent (takes precedence): --[no-]install-ghc flag

Whether or not to automatically install GHC when necessary.

jobs

Default: the number of CPUs (cores) that the machine has.

Command line equivalent (takes precedence): -j, --jobs option

Specifies the number of concurrent jobs (principally, Stack actions during building - see further below) to run.

When building GHC from source, specifies the -j[<n>] flag of GHC's Hadrian build system.

In some circumstances, the default can cause some machines to run out of memory during building. If those circumstances arise, specify jobs: 1.

This configuration option is distinct from GHC's own -j[<n>] flag, which relates to parallel compilation of modules within a package.

local-bin-path

Default (on Unix-like operating systems): ~/.local/bin

Default (on Windows): %APPDATA%\local\bin

Command line equivalent (takes precedence): --local-bin-path option

Specifies the target directory for stack build --copy-bins and stack install. An absolute or relative path can be specified.

If the project-level configuration is provided in the global-project directory in the Stack root, a relative path is assumed to be relative to the current directory. Otherwise, it is assumed to be relative to the directory of the project-level configuration file.

local-programs-path

:octicons-tag-24: 1.3.0

This overrides the location of the Stack 'programs' directory, where tools like GHC get installed. The path must be an absolute one.

Stack's defaults differ between Unix-like operating systems and Windows.

=== "Unix-like"

Default: `programs` directory in the [Stack root](stack_root.md).

=== "Windows"

Default: `%LOCALAPPDATA%\Programs\stack`, if the `%LOCALAPPDATA%`
environment variable exists. Otherwise, the `programs` directory in the
[Stack root](stack_root.md).

The MSYS2 tool is also installed in the Stack 'programs' directory.

!!! warning

    If there is a space character in the path to Stack's 'programs'
    directory this may cause problems with building packages that make use
    of the GNU project's `autoconf` package and `configure` shell script
    files. That may be the case particularly if there is no corresponding
    short name ('8 dot 3' name) for the directory in the path with the space
    (which may be the case if '8 dot 3' names have been stripped or their
    creation not enabled by default). If there are problems building, it
    will be necessary to specify an alternative path that does not contain
    space characters. Examples of packages on Hackage that make use of
    `configure` are `network` and `process`.

modify-code-page

:octicons-tag-24: 0.1.10.0

Restrictions: Windows systems only.

Default: true

Command line equivalent (takes precedence): --[no-]modify-code-page flag

Whether to modify the code page for UTF-8 output.

modify-code-page: false

msys-environment

:octicons-tag-24: UNRELEASED

Restrictions: Windows systems only.

Default: MINGW64 (64-bit Windows) or MINGW32 (32-bit Windows)

The name of the MSYS2 environment (case-sensitive) used in the Stack environment. Valid environments are CLANG32, CLANG64, CLANGARM64, MINGW32, MINGW64, and UCRT64.

nix

Default:

nix:
  enable: false # Except on NixOS, where `enable: true`
  pure: true
  packages: []
  shell-file:
  nix-shell-options: []
  path: []
  add-gc-roots: false

Command line equivalents: --nix-* flags and options (see stack --nix-help for details).

For further information, see the Nix integration documentation.

notify-if-arch-unknown

Default: true

If the specified machine architecture value is unknown to Cabal (the library), should Stack notify the user of that?

notify-if-cabal-untested

Default: true

If Stack has not been tested with the version of Cabal (the library) that has been found, should Stack notify the user of that?

notify-if-ghc-untested

Default: true

If Stack has not been tested with the version of GHC that is being used, should Stack notify the user of that?

notify-if-nix-on-path

:octicons-tag-24: 0.1.5.0

Default: true

If Stack's integration with the Nix package manager is not enabled, should Stack notify the user if a nix executable is on the PATH?

package-index

:octicons-tag-24: 2.9.3

Default:

package-index:
  download-prefix: https://hackage.haskell.org/
  hackage-security:
    keyids:
    - 0a5c7ea47cd1b15f01f5f51a33adda7e655bc0f0b0615baa8e271f4c3351e21d
    - 1ea9ba32c526d1cc91ab5e5bd364ec5e9e8cb67179a471872f6e26f0ae773d42
    - 2c6c3627bd6c982990239487f1abd02e08a02e6cf16edb105a8012d444d870c3
    - 51f0161b906011b52c6613376b1ae937670da69322113a246a09f807c62f6921
    - fe331502606802feac15e514d9b9ea83fee8b6ffef71335479a2e68d84adc6b0
    key-threshold: 3
    ignore-expiry: true

Specify the package index. The index must use the Hackage Security format. This setting is most useful for providing a mirror of the official Hackage server for

bypassing a firewall; or
faster downloads.

If the setting specifies an index that does not mirror Hackage, it is likely that will result in significant breakage, including most snapshots failing to work.

In the case of Hackage, the keys of its root key holders are contained in the haskell-infra/hackage-root-keys repository. The Hackage package index is signed. A signature is valid when three key holders have signed. The Hackage timestamp is also signed. A signature is valid when one key holder has signed.

If the hackage-security key is absent, the Hackage Security configuration will default to that for the official Hackage server.

key-threshold specifies the minimum number of keyholders that must have signed the package index for it to be considered valid.

ignore-expiry specifies whether or not the expiration of timestamps should be ignored.

!!! info

Before Stack 2.1.3, the default for `ignore-expiry` was `false`. For more
information, see
[issue #4928](https://github.com/commercialhaskell/stack/issues/4928).

pvp-bounds

Default: none

Command line equivalent (takes precedence): stack sdist --pvp-bounds option or stack upload --pvp-bounds option

!!! warning

As of Stack 1.6.0, this feature does not reliably work, due to issues with
the Cabal library's printer. Stack will generate a warning when a lossy
conversion occurs, in which case you may need to disable this setting. For
further information, see issue
[#3550](https://github.com/commercialhaskell/stack/issues/3550).

When using the sdist and upload commands, this setting determines whether the Cabal file's dependencies should be modified to reflect PVP lower and upper bounds.

Basic use

Values are none (unchanged), upper (add upper bounds), lower (add lower bounds), and both (and upper and lower bounds). The algorithm Stack follows is:

If an upper or lower bound (other than >= 0 - 'any version') already exists on a dependency, it is left alone
When adding a lower bound, Stack looks at the current version specified by stack.yaml, and sets it as the lower bound (e.g., foo >= 1.2.3)
When adding an upper bound, Stack sets it as less than the next major version (e.g., foo < 1.3)

pvp-bounds: none

For further information, see the announcement blog post.

Use with Cabal file revisions

:octicons-tag-24: 1.5.0

Each of the values listed above supports adding -revision to the end of the value, e.g. pvp-bounds: both-revision. This means that, when uploading to Hackage, Stack will first upload your tarball with an unmodified Cabal file, and then upload a Cabal file revision with the PVP bounds added.

This can be useful - especially combined with the Stackage no-revisions feature - as a method to ensure PVP compliance without having to proactively fix bounds issues for Stackage maintenance.

recommend-stack-upgrade

Default: true

When Stack notices that a new version of Stack is available, should it notify the user?

rebuild-ghc-options