This page is intended to fully document all configuration options available in the stack.yaml file. Note that this page is likely to be both incomplete and sometimes inaccurate. If you see such cases, please update the page, and if you're not sure how, open an issue labeled "question".
The stack.yaml configuration options break down into project specific options in:
<project dir>/stack.yaml
and non-project specific options in:
/etc/stack/config.yaml
-- for system global non-project default options~/.stack/config.yaml
-- for user non-project default options- The project file itself may also contain non-project specific options
Note: When stack is invoked outside a stack project it will source project specific options from ~/.stack/global/stack.yaml
. Options in this file will be ignored for a project with its own <project dir>/stack.yaml
.
Project specific options are only valid in the stack.yaml
file local to a project, not in the user or global config files.
This lists all local packages. In the simplest usage, it will be a list of directories, e.g.:
packages:
- dir1
- dir2
- dir3
However, it supports two other location types: an HTTP URL referring to a tarball that can be downloaded, and information on a Git repo to clone, together with this SHA1 commit. For example:
packages:
- some-directory
- https://example.com/foo/bar/baz-0.0.2.tar.gz
- location:
git: git@github.com:commercialhaskell/stack
commit: 6a86ee32e5b869a877151f74064572225e1a0398
Note: it is highly recommended that you only use SHA1 values for a Git commit. Other values may work, but they are not officially supported, and may result in unexpected behavior (namely, stack will not automatically pull to update to new versions).
stack further allows you to tweak your packages by specifying two additional settings:
- A list of subdirectories to build (useful for mega-repos like wai or digestive-functors)
- Whether a package should be treated as a dependency: a package marked
extra-dep: true
will only be built if demanded by a non-dependency, and its test suites and benchmarks will not be run. This is useful for tweaking upstream packages.
To tie this all together, here's an example of the different settings:
packages:
- local-package
- location: vendor/binary
extra-dep: true
- location:
git: git@github.com:yesodweb/wai
commit: 2f8a8e1b771829f4a8a77c0111352ce45a14c30f
subdirs:
- auto-update
- wai
This is a list of package identifiers for additional packages from upstream to be included. This is usually used to augment an LTS Haskell or Stackage Nightly snapshot with a package that is not present or is at an older version than you wish to use.
extra-deps:
- acme-missiles-0.3
Specifies how dependencies are resolved. There are currently four resolver types:
- LTS Haskell snapshots, e.g.
resolver: lts-2.14
- Stackage Nightly snapshot, e.g.
resolver: nightly-2015-06-16
- No snapshot, just use packages shipped with the compiler
- For GHC this looks like
resolver: ghc-7.10.2
- For GHCJS this looks like
resolver: ghcjs-0.1.0_ghc-7.10.2
.
- For GHC this looks like
- Custom snapshot
Each of these resolvers will also determine what constraints are placed on the compiler version. See the compiler-check option for some additional control over compiler version.
Flags can be set for each package separately, e.g.
flags:
package-name:
flag-name: true
Flags will only affect packages in your packages
and extra-deps
settings.
Packages that come from the snapshot global database or are not affected.
The image settings are used for the creation of container images using stack container image
, e.g.
image:
container:
base: "fpco/stack-build"
add:
static: /data/static
base
is the docker image that will be used to built upon. The add
lines allow you to add additional directories to your image. You can also specify entrypoints
. Your executables are placed in /usr/local/bin
.
Non-project config options may go in the global config (/etc/stack/config.yaml
) or the user config (~/.stack/config.yaml
).
See Docker configuration.
Integer indicating how many simultaneous downloads are allowed to happen
Default: 8
Strip out the "Loading ..." lines from GHC build output, produced when using Template Haskell
Default: true
URL providing a JSON with information on the latest LTS and Nightly snapshots, used for automatic project configuration.
Default: https://www.stackage.org/download/snapshots.json
Target directory for stack install
and stack build --copy-bins
.
Default: ~/.local/bin
package-indices:
- name: Hackage
download-prefix: https://s3.amazonaws.com/hackage.fpcomplete.com/package/
# at least one of the following must be present
git: https://github.com/commercialhaskell/all-cabal-hashes.git
http: https://s3.amazonaws.com/hackage.fpcomplete.com/00-index.tar.gz
# optional fields, both default to false
gpg-verify: false
require-hashes: false
One thing you should be aware of: if you change the contents of package-version combination by setting a different package index, this can have an effect on other projects by installing into your shared snapshot database.
Enables or disables using the GHC available on the PATH. Useful to disable if
you want to force stack to use its own installed GHC (via stack setup
), in
cases where your system GHC my be incomplete for some reason. Default is true
.
# Turn off system GHC
system-ghc: false
Whether or not to automatically install GHC when necessary. Default is false
,
which means stack will prompt you to run stack setup
as needed.
Should we skip the check to confirm that your system GHC version (on the PATH) matches what your project expects? Default is false
.
Require a version of stack within the specified range
(cabal-style)
to be used for this project. Example: require-stack-version: "== 0.1.*"
Default: "-any"
Set the architecture and operating system for GHC, build directories, etc. Values are those recognized by Cabal, e.g.:
arch: i386, x86_64
os: windows, linux
You likely only ever want to change the arch value. This can also be set via the command line.
A list of extra paths to be searched for header files and libraries, respectively. Paths should be absolute
extra-include-dirs:
- /opt/foo/include
extra-lib-dirs:
- /opt/foo/lib
(Since 0.1.4)
Specifies how the compiler version in the resolver 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. This is the defaultmatch-exact
: the entire version number must match preciselynewer-minor
: the third component can be increased, e.g. if your resolver isghc-7.10.1
, then 7.10.2 will also be allowed. This was the default up through stack 0.1.3
(Since 0.1.4)
Allows specifying per-package and global GHC options:
ghc-options:
# All packages
"*": -Wall
some-package: -DSOME_CPP_FLAG
Caveat emptor: setting options like this will affect your snapshot packages,
which can lead to unpredictable behavior versus official Stackage snapshots.
This is in contrast to the ghc-options
command line flag, which will only
affect local targets.
(Since 0.1.5)
Specify a variant binary distribution of GHC to use. Known values:
standard
: This is the default, uses the standard GHC binary distributiongmp4
: Use the "centos6" GHC bindist, for Linux systems with libgmp4 (akalibgmp.so.3
), such as CentOS 6. This variant will be used automatically on such systems; you should not need to specify it in the configurationintegersimple
: Use a GHC bindist that uses integer-simple instead of GMP- any other value: Use a custom GHC bindist. You should specify
setup-info so
stack setup
knows where to download it, or pass thestack setup --ghc-bindist
argument on the command-line
(Since 0.1.5)
Allows overriding from where tools like GHC and msys2 (on Windows) are downloaded. Most useful for specifying locations of custom GHC binary distributions (for use with the ghc-variant option):
setup-info:
ghc:
windows32-custom-foo:
7.10.2:
url: "https://example.com/ghc-7.10.2-i386-unknown-mingw32-foo.tar.xz"
(Since 0.1.5)
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. Values are none
(unchanged), upper
(add upper bounds), lower
(add
lower bounds), and both (and upper and lower bounds). The algorithm it follows
is:
- If an upper or lower bound already exists on a dependency, it's left alone
- When adding a lower bound, we look at the current version specified by stack.yaml, and set it as the lower bound (e.g.,
foo >= 1.2.3
) - When adding an upper bound, we require less than the next major version (e.g.,
foo < 1.3
)
pvp-bounds: none
For more information, see the announcement blog post.
(Since 0.1.6)
Modify the code page for UTF-8 output when running on Windows. Default behavior is to modify.
modify-code-page: false
(Since 0.1.6)
Decide whether a custom Setup.hs
script should be run with an explicit list
of dependencies based on the dependencies of the package itself, or simply
provided the global package database. This option is most often needed when
overriding packages in the global database, see issue #1110.
Setting the list explicitly can help when a Setup.hs depends on packages in the local package database. For more information on that case, see issue #897.
Note that in the future, this should all disappear once Cabal provides full support for explicit Setup.hs dependencies.
explicit-setup-deps:
"*": true # change the default
entropy: false # override the new default for one package
(Since 0.1.6)
Should we rebuild a package when its GHC options change? Before 0.1.6, this was a non-configurable true. However, in most cases, the flag is used to affect optimization levels and warning behavior, for which GHC itself doesn't actually recompile the modules anyway. Therefore, the new behavior is to not recompile on an options change, but this behavior can be changed back with the following:
rebuild-ghc-options: true
(Since 0.1.6)
Which packages do ghc-options on the command line get applied to? Before 0.1.6, the default value was targets
apply-ghc-options: locals # all local packages, the default
# apply-ghc-options: targets # all local packages that are targets
# apply-ghc-options: everything # applied even to snapshot and extra-deps
Note that everything
is a slightly dangerous value, as it can break invariants about your snapshot database.