config_command.md

The stack config commands

stack config COMMAND

Available commands:
  build-files              Generate (when applicable) a Cabal file from a
                           package description in the Hpack format and/or a lock
                           file for Stack's project-level configuration.
  env                      Print environment variables for use in a shell.
  set                      Set a key in a configuration file to value.

The stack config commands provide assistance with accessing or modifying Stack's configuration. See stack config for the available commands.

The stack config build-files command

stack config build-files

stack config build-files generates (when applicable):

• a Cabal file from a package description in the Hpack format (package.yaml); and/or

• a lock file for Stack's project-level configuration (by default, stack.yaml);

without taking any other build steps.

The stack config env command

stack config env [--[no-]locals] [--[no-]ghc-package-path] [--[no-]stack-exe]
                 [--[no-]locale-utf8] [--[no-]keep-ghc-rts]

stack config env outputs a script that sets or unsets environment variables for a Stack environment. Flags modify the script that is output:

• --[no-]locals (enabled by default) include/exclude project package information
• --[no-]ghc-package-path (enabled by default) set GHC_PACKAGE_PATH environment variable or not
• --[no-]stack-exe (enabled by default) set STACK_EXE environment variable or not
• --[no-]locale-utf8 (disabled by default) set the GHC_CHARENC environment variable to UTF-8 or not
• --[no-]keep-ghc-rts (disabled by default) keep/discard any GHCRTS environment variable

The command also accepts flags and options of the stack build command that affect the location of the local project installation directory, such as --profile and --no-strip. For further information, see the documentation of the project Stack work directory.

The stack config set commands

stack config set COMMAND

Available commands:
  install-ghc              Configure whether or not Stack should automatically
                           install GHC when necessary.
  install-msys             Configure whether or not Stack should automatically
                           install MSYS2 when necessary.
  package-index            Configure Stack's package index
  recommend-stack-upgrade  Configure whether or not Stack should notify the user
                           if it identifes a new version of Stack is available.
  resolver                 Change the snapshot of the current project, using the
                           resolver key.
  snapshot                 Change the snapshot of the current project.
  system-ghc               Configure whether or not Stack should use a system
                           GHC installation.

The stack config set commands allow the values of keys in configuration files to be set. See stack config set for the available keys.

!!! note

The `config set` commands support an existing key only in the form
`key: value` on a single line.

The stack config set install-ghc command

stack config set install-ghc [--global] true|false

stack config set install-ghc true or false sets the install-ghc non-project specific configuration option in a configuration file, accordingly. By default, the project-level configuration file (stack.yaml, by default) is altered. The --global flag specifies the user-specific global configuration file (config.yaml).

The stack config set install-msys command

:octicons-tag-24: 3.5.1

stack config set install-msys [--global] true|false

stack config set install-msys true or false sets the install-msys non-project specific configuration option in a configuration file, accordingly. By default, the project-level configuration file (stack.yaml, by default) is altered. The --global flag specifies the user-specific global configuration file (config.yaml).

The stack config set package-index download-prefix command

:octicons-tag-24: 2.9.3

stack config set package-index download-prefix [--global] [URL]

stack config set package-index download-prefix <url> sets the download-prefix key of the package-index non-project specific configuration option in a configuration file, accordingly. By default, the project-level configuration file (stack.yaml, by default) is altered. The --global flag specifies the user-specific global configuration file (config.yaml).

The stack config set recommend-stack-upgrade command

stack config set recommend-stack-upgrade [--project] true|false

stack config set recommend-stack-upgrade true or false sets the recommend-stack-upgrade non-project specific configuration option in a configuration file, accordingly. By default, the user-specific global configuration file (config.yaml) is altered. The --project flag specifies the project-level configuration file (stack.yaml, by default).

The stack config set resolver command

stack config set resolver SNAPSHOT

A command corresponding to the stack config set snapshot command but using the resolver key instead of the snapshot key.

The stack config set snapshot command

:octicons-tag-24: 2.15.1

stack config set snapshot SNAPSHOT

stack config set snapshot <snapshot> sets the snapshot project-specific configuration option in the project-level configuration file (stack.yaml, by default) to the specified snapshot.

A snapshot of lts or nightly will be translated into the most recent available. A snapshot of lts-22 will be translated into the most recent available in the lts-22 sequence.

If a resolver key is present, it will be replaced by a snapshot key.

The stack config set system-ghc command

stack config set system-ghc [--global] true|false

stack config set system-ghc true or false sets the system-ghc non-project specific configuration option in a configuration file, accordingly. By default, the project-level configuration file (stack.yaml, by default) is altered. The --global flag specifies the user-specific global configuration file (config.yaml).