global_flags.md

Stack's global flags and options

Stack can also be configured by flags and options on the command line. Global flags and options apply to all of Stack's commands. In addition, all of Stack's commands accept the --setup-info-yaml and --snapshot-location-base options and the --help flag.

--allow-different-user flag

Restrictions: POSIX systems only

Default: True, if inside Docker; false otherwise

Enable/disable permitting users other than the owner of the Stack root directory to use a Stack installation. For further information, see the documentation for the corresponding non-project specific configuration option.

--arch option

Pass the option --arch <architecture> to specify the relevant machine architecture. For further information, see the documentation for the corresponding non-project specific configuration option.

--color or -colour options

Pass the option stack --color <when> to specify when to use color in output. For further information, see the documentation for the corresponding non-project specific configuration option.

--compiler option

Pass the option --compiler <compiler> to specify the compiler. For further information, see the YAML configuration documentation.

--custom-preprocessor-extensions option

Pass the option --custom-preprocessor-extensions <extension> to specify an extension used for a custom preprocessor. For further information, see the documentation for the corresponding non-project specific configuration option.

--docker* flags and options

Stack supports automatically performing builds inside a Docker container. For further information see stack --docker-help or the Docker integratiom documentation.

--[no-]dump-logs flag

Default: Dump warning logs

Enables/disables the dumping of the build output logs for project packages to the console. For further information, see the documentation for the corresponding non-project specific configuration option.

--extra-include-dirs option

Pass the option --extra-include-dirs <director> to specify an extra directory to check for C header files. The option can be specified multiple times. For further information, see the documentation for the corresponding non-project specific configuration option.

--extra-lib-dirs option

Pass the option --extra-lib-dirs <director> to specify an extra directory to check for libraries. The option can be specified multiple times. For further information, see the documentation for the corresponding non-project specific configuration option.

--ghc-build option

Pass the option --ghc-build <build> to specify the relevant specialised GHC build. For further information, see the documentation for the corresponding non-project specific configuration option.

--ghc-variant option

Pass the option --ghc-variant <variant> to specify the relevant GHC variant. For further information, see the documentation for the corresponding non-project specific configuration option.

--hpack-numeric-version flag

Pass the flag --hpack-numeric-version to cause Stack to report the numeric version of its built-in Hpack library to the standard output stream (e.g. 0.35.0) and quit.

--[no-]install-ghc flag

Default: Enabled

Enables/disables the download and instalation of GHC if necessary. For further information, see the documentation for the corresponding non-project specific configuration option.

--jobs or -j option

Pass the option --jobs <number_of_jobs> to specify the number of concurrent jobs (Stack actions during building) to run.

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

By default, Stack specifies a number of concurrent jobs equal to the number of CPUs (cores) that the machine has. In some circumstances, that 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.

For further information, see the documentation for the corresponding non-project specific configuration option: jobs.

--local-bin-path option

Pass the option --local-bin-path <directory> to set the target directory for stack build --copy-bins and stack install. An absolute or relative path can be specified. A relative path at the command line is always assumed to be relative to the current directory.

For further information, see the documentation for the corresponding non-project specific configuration option.

--lock-file option

Default: read-write, if snapshot specified in YAML configuration file; read-only, if a different snapshot is specified on the command line.

Pass the option --lock-file <mode> to specify how Stack interacts with lock files. Valid modes are:

• error-on-write: Stack reports an error, rather than write a lock file;
• ignore: Stack ignores lock files;
• read-only: Stack only reads lock files; and
• read-write: Stack reads and writes lock files.

--[no-]modify-code-page flag

Restrictions: Windows systems only

Default: Enabled

Enables/disables setting the codepage to support UTF-8. For further information, see the documentation for the corresponding non-project specific configuration option.

--nix* flags and options

Stack can be configured to integrate with Nix. For further information, see stack --nix-help or the Nix integration documentation.

--numeric-version flag

Pass the flag --numeric-version to cause Stack to report its numeric version to the standard output stream (e.g. 2.9.1) and quit.

--[no-]plan-in-log flag

:octicons-tag-24: 2.13.1

Default: Disabled

Enables/disables the logging of build plan construction in debug output. Information about the build plan construction can be lengthy. If you do not need it, it is best omitted from the debug output.

--resolver option

A synonym for the --snapshot option to specify the snapshot resolver.

--[no-]rsl-in-log flag

:octicons-tag-24: 2.9.1

Default: Disabled

Enables/disables the logging of the raw snapshot layer (rsl) in debug output. Information about the raw snapshot layer can be lengthy. If you do not need it, it is best omitted from the debug output.

--[no-]script-no-run-compile flag

Default: Disabled

Enables/disables the use of options --no-run --compile with the stack script command.

--silent flag

Equivalent to the --verbosity silent option.

--[no-]skip-ghc-check option

Default: Disabled

Enables/disables the skipping of checking the GHC version and architecture. For further information, see the documentation for the corresponding non-project specific configuration option.

--[no-]skip-msys option

Restrictions: Windows systems only

Default: Disabled

Enables/disables the skipping of checking for the Stack-supplied MSYS2 (and installing that MSYS2, if it is not installed) when Stack is setting up the environment. For further information, see the documentation for the corresponding non-project specific configuration option.

--snapshot option

:octicons-tag-24: 2.15.1

Pass the option --snapshot <snapshot> to specify the snapshot. For further information, see the YAML configuration documentation.

At the command line (only):

• --snapshot lts-<major_version> specifies the latest Stackage LTS Haskell snapshot with the specified major version;
• --snapshot lts specifies, from those with the greatest major version, the latest Stackage LTS Haskell snapshot;
• --snapshot nightly specifies the most recent Stackage Nightly snapshot; and
• --snapshot global specifies the snapshot specified by the project-level configuration file in the global-project directory in the Stack root.

--stack-colors or --stack-colours options

Pass the option --stack-colors <styles> to specify Stack's output styles. For further information, see the documentation for the corresponding non-project specific configuration option.

--stack-root option

Overrides: STACK_ROOT environment variable

Pass the option --stack-root <absolute_path_to_the_Stack_root> to specify the path to the Stack root directory. The path must be an absolute one.

--stack-yaml option

Default: stack.yaml

Overrides: STACK_YAML enviroment variable

Pass the option --stack-yaml <file> to specify Stack's project-level YAML configuration file.

--[no-]system-ghc flag

Default: Disabled

Enables/disables the use of a GHC executable on the PATH, if one is available and its version matches.

--[no-]terminal flag

Default: Stack is running in a terminal (as detected)

Enables/disables whether Stack is running in a terminal.

--terminal-width option

Default: the terminal width (if detected); otherwise 100

Pass the option --terminal-width <width> to specify the width of the terminal, used by Stack's pretty printed messages.

--[no-]time-in-logs flag

Default: Enabled

Enables/disables the inclusion of time stamps against logging entries when the verbosity level is 'debug'.

--verbose or -v flags

Equivalent to the --verbosity debug option.

--verbosity option

Default: info

Pass the option --verbosity <log_level> to specify the level for logging. Possible levels are silent, error, warn, info and debug, in order of increasing amounts of information provided by logging.

--version flag

Pass the flag --version to cause Stack to report its version to standard output and quit. For versions that are release candidates, the report will list the dependencies that Stack has been compiled with.

--with-gcc option

Pass the option --with-gcc <path_to_gcc> to specify use of a GCC executable. For further information, see the documentation for the corresponding non-project specific configuration option.

--with-hpack option

Pass the option --with-hpack <hpack> to specify use of an Hpack executable. For further information, see the documentation for the corresponding non-project specific configuration option.

--work-dir option

Default: .stack-work

Overrides: STACK_WORK environment variable, and work-dir non-project specific configuration option.

Pass the option --work-dir <relative_path_to_the_Stack_root> to specify the path to Stack's work directory, within a local project or package directory. The path must be a relative one, relative to the the root directory of the project or package. The relative path cannot include a .. (parent directory) component.

--setup-info-yaml command option

Default: https://raw.githubusercontent.com/commercialhaskell/stackage-content/master/stack/stack-setup-2.yaml

The --setup-info-yaml <url> command option specifies the location of a setup-info dictionary. The option can be specified multiple times.

--snapshot-location-base command option

Default: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master

The --snapshot-location-base <url> command option specifies the base location of snapshots.

--help command flag

If Stack is passed the --help command flag, it will output help for the command.