The environment variables listed in alphabetal order below can affect how Stack behaves.
Stack will use the value of the GH_TOKEN or, in the alternative,
GITHUB_TOKEN environment variable (if not an empty string) as credentials to
authenticate its requests of the GitHub REST API, using HTTP 'Basic'
authentication.
GitHub limits the rate of unauthenticated requests to its API, although most users of Stack will not experience that limit from the use of Stack alone. The limit for authenticated requests is significantly higher.
For more information about authentication of requests of the GitHub REST API, see GitHub's REST API documentation.
Related command: stack upload
Hackage allows its members to register an API authentification token and to authenticate using the token.
A Hackage API authentification token can be used with stack upload instead of
username and password, by setting the HACKAGE_KEY environment variable. For
example:
=== "Unix-like"
~~~text
HACKAGE_KEY=<api_authentification_token>
stack upload .
~~~
=== "Windows (with PowerShell)"
~~~text
$Env:HACKAGE_KEY=<api_authentification_token>
stack upload .
~~~
Related command: stack upload
stack upload will request a Hackage username and password to authenticate.
This can be avoided by setting the HACKAGE_USERNAME and HACKAGE_PASSWORD
environment variables. For
example:
=== "Unix-like"
~~~text
export $HACKAGE_USERNAME="<username>"
export $HACKAGE_PASSWORD="<password>"
stack upload .
~~~
=== "Windows (with PowerShell)"
~~~text
$Env:HACKAGE_USERNAME='<username>'
$Env:HACKAGE_PASSWORD='<password>'
stack upload .
~~~
Related command: all commands that can produce colored output using control character sequences.
Stack follows the standard at http://no-color.org/. Stack checks for a
NO_COLOR environment variable. When it is present and not an empty string
(regardless of its value), Stack prevents the addition of control character
sequences for color to its output.
Related command: all commands that make use of Stack's global YAML configuration
file (config.yaml).
Overridden by: Stack's global
--stack-root option.
The environment variable STACK_ROOT can be used to specify the
Stack root directory.
Related command: all commands that make use of Stack's work directories.
Overridden by: Stack's work-dir non-project
specific configuration option, or global
--work-dir option.
The environment variable STACK_WORK can be used to specify the path of Stack's
work directory, within a local project or package directory, and override
Stack's default of .stack-work. The path must be a relative one, relative to
the root directory of the project or package. The relative path cannot include a
.. (parent directory) component.
Related command: all commands that make use of Stack's user-specific general
YAML configuration file (config.yaml).
Overridden by: the use of Stack's STACK_ROOT environment variable, or the use
of Stack's global
--stack-root option.
On Unix-like operating systems and Windows, Stack can be configured to follow
the XDG Base Directory Specification if the environment variable STACK_XDG is
set to any non-empty value.
Related command: all commands that make use of Stack's project-level YAML configuration file.
Overridden by: Stack's global
--stack-yaml option.
The environment variable STACK_YAML can be used to specify Stack's
project-level YAML configuration file.