Skip to content

The stack exec command

stack exec COMMAND
           [-- ARGUMENT(S) (e.g. stack exec ghc-pkg -- describe base)]
           [--[no-]ghc-package-path] [--[no-]stack-exe] [--package PACKAGE]
           [--rts-options RTSFLAG] [--cwd DIR]

stack exec executes the specified executable as a command in the Stack environment. If an executable is not specified, the first argument after -- is taken to be the executable. Otherwise, all arguments after -- are taken to be command line arguments for the specified executable.

By default:

  • the GHC_PACKAGE_PATH environment variable is set for the command's process. Pass the flag --no-ghc-package-path to not set the environment variable;

  • if the operating system provides a reliable way to determine it and where a result was available, the STACK_EXE environment variable is set to the path to the current Stack executable for the command's process. Pass the flag --no-stack-exe to not set the environment variable; and

  • the specified executable is executed in the current directory. Pass the option --cwd <directory> to execute the executable in the specified directory.

The option --package <package> has no effect for the stack exec command. For further information about its use, see the stack ghc command documentation or the stack runghc command documentation.

Pass the option --rts-option <rts_flag(s)> to specify a GHC RTS flag or option. The option can be specified multiple times. All specified GHC RTS flags and options are added to the arguments for the specified executable between arguments +RTS and -RTS.

Specified GHC RTS flags and options are separated by spaces. Items can be unquoted (if they do not contain space or " characters) or quoted (""). Quoted items can include 'escaped' characters, escaped with an initial \ character.

Account may need to be taken of the shell's approach to the processing of command line arguments. For example, to pass 'a single quoted string':

In Bash, or Zsh (if RC_QUOTES option not set):

stack exec <command> -- \''a single quoted string'\'

Outside of single quotes, \' escapes a single quote. The content of single quotes is taken literally, but cannot contain a single quote.

In Zsh (if RC_QUOTES option set):

stack exec <command> -- '''a single quoted string'''

The content of single quotes is taken literally. Within single quotes, '' escapes a single quote.

In PowerShell:

stack exec <command> -- '''a single quoted string'''

The content of single quotes is taken literally. Within single quotes, '' escapes a single quote.

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.