# 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](stack_root.md) directory to use a Stack installation. For further information, see the documentation for the corresponding non-project specific configuration [option](yaml_configuration.md#allow-different-user). ## `--arch` option Pass the option `--arch ` to specify the relevant machine architecture. For further information, see the documentation for the corresponding non-project specific configuration [option](yaml_configuration.md#arch). ## `--color` or `-colour` options Pass the option `stack --color ` to specify when to use color in output. For further information, see the documentation for the corresponding non-project specific configuration [option](yaml_configuration.md#color). ## `--compiler` option Pass the option `--compiler ` to specify the compiler. For further information, see the [YAML configuration](yaml_configuration.md#compiler) documentation. ## `--custom-preprocessor-extensions` option Pass the option `--custom-preprocessor-extensions ` to specify an extension used for a custom preprocessor. For further information, see the documentation for the corresponding non-project specific configuration [option](yaml_configuration.md#custom-preprocessor-extensions). ## `--docker*` flags and options Stack supports automatically performing builds inside a Docker container. For further information see `stack --docker-help` or the [Docker integratiom](docker_integration.md) documentation. ## `--[no-]dump-logs` flag Default: Dump warning logs Enables/disables the dumping of the build output logs for local packages to the console. For further information, see the documentation for the corresponding non-project specific configuration [option](yaml_configuration.md#dump-logs). ## `--extra-include-dirs` option Pass the option `--extra-include-dirs ` 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](yaml_configuration.md#extra-include-dirs). ## `--extra-lib-dirs` option Pass the option `--extra-lib-dirs ` 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](yaml_configuration.md#extra-lib-dirs). ## `--ghc-build` option Pass the option `--ghc-build ` to specify the relevant specialised GHC build. For further information, see the documentation for the corresponding non-project specific configuration [option](yaml_configuration.md#ghc-build). ## `--ghc-variant` option Pass the option `--ghc-variant ` to specify the relevant GHC variant. For further information, see the documentation for the corresponding non-project specific configuration [option](yaml_configuration.md#ghc-variant). ## `--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](yaml_configuration.md#install-ghc). ## `--jobs` or `-j` option Pass the option `--jobs ` to specify the number of concurrent jobs (Stack actions during building) to run. When [building GHC from source](yaml_configuration.md#building-ghc-from-source), specifies the `-j[]` 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[]` 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`](yaml_configuration.md#jobs). ## `--local-bin-path` option Pass the option `--local-bin-path ` to set the target directory for [`stack build --copy-bins`](build_command.md#-no-copy-bins-flag) 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](yaml_configuration.md#local-bin-path). ## `--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 ` 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](yaml_configuration.md#modify-code-page). ## `--nix*` flags and options Stack can be configured to integrate with Nix. For further information, see `stack --nix-help` or the [Nix integration](nix_integration.md) 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](https://github.com/commercialhaskell/stack/releases/tag/v2.13.1) 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 Pass the option `--resolver ` to specify the snapshot. For further information, see the [YAML configuration](yaml_configuration.md#resolver-or-snapshot) documentation. At the command line (only): * `--resolver lts-` specifies the latest Stackage LTS Haskell snapshot with the specified major version; * `--resolver lts` specifies, from those with the greatest major version, the latest Stackage LTS Haskell snapshot; and * `--resolver nightly` specifies the most recent Stackage Nightly snapshot. ## `--[no-]rsl-in-log` flag [:octicons-tag-24: 2.9.1](https://github.com/commercialhaskell/stack/releases/tag/v2.9.1) 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](script_command.md). ## `--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](yaml_configuration.md#skip-ghc-check). ## `--[no-]skip-msys` option Restrictions: Windows systems only Default: Disabled Enables/disables the skipping of installing MSYS2. For further information, see the documentation for the corresponding non-project specific configuration [option](yaml_configuration.md#skip-msys). ## `--stack-colors` or `--stack-colours` options Pass the option `--stack-colors ` to specify Stack's output styles. For further information, see the documentation for the corresponding non-project specific configuration [option](yaml_configuration.md#stack-colors). ## `--stack-root` option Overrides: `STACK_ROOT` environment variable Pass the option `--stack-root ` to specify the path to the [Stack root](stack_root.md) directory. The path must be an absolute one. ## `--stack-yaml` option Default: `stack.yaml` Overrides: `STACK_YAML` enviroment variable Pass the option `--stack-yaml ` 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 ` 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 ` 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 ` to specify use of a GCC executable. For further information, see the documentation for the corresponding non-project specific configuration [option](yaml_configuration.md#with-gcc). ## `--with-hpack` option Pass the option `--with-hpack ` to specify use of an Hpack executable. For further information, see the documentation for the corresponding non-project specific configuration [option](yaml_configuration.md#with-hpack). ## `--work-dir` option Default: `.stack-work` Overrides: [`STACK_WORK`](environment_variables.md#stack_work) environment variable, and [`work-dir`](yaml_configuration.md) non-project specific configuration option. Pass the option `--work-dir ` 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 ` 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 ` 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.