Show all the special environment variables
available for customizing targets.
Value
A data frame with one row per environment variable
and columns with the name and current value of each.
An unset environment variable will have a value of ""
by default. (Customize with the unset argument).
Details
You can customize the behavior of targets
with special environment variables. The sections in this help file
describe each environment variable, and the tar_envvars() function
lists their current values.
If you modify environment variables, please set them
in project-level .Renviron file so you do not lose your
configuration when you restart your R session.
Modify the project-level .Renviron file with
usethis::edit_r_environ(scope = "project"). Restart
your R session after you are done editing.
For targets that run on parallel workers
created by tar_make_clustermq() or tar_make_future(),
only the environment variables listed by tar_envvars()
are specifically exported to the targets.
For all other environment variables, you will have to set
the values manually, e.g. a project-level .Renviron file
(for workers that have access to the local file system).
TAR_ASK
The TAR_ASK environment variable accepts values "true" and "false".
If TAR_ASK is not set, or if it is set to "true",
then targets asks permission in a menu
before overwriting certain files, such as the target script file
(default: _targets.R) in tar_script().
If TAR_ASK is "false", then targets overwrites the old files
with the new ones without asking. Once you are comfortable with
tar_script(), tar_github_actions(), and similar functions,
you can safely set TAR_ASK to "false" in either a project-level
or user-level .Renviron file.
TAR_CONFIG
The TAR_CONFIG environment variable controls the file path to the
optional YAML configuration file with project settings.
See the help file of tar_config_set() for details.
TAR_PROJECT
The TAR_PROJECT environment variable sets the name of project
to set and get settings when working with the YAML configuration file.
See the help file of tar_config_set() for details.
TAR_WARN
The TAR_WARN environment variable accepts values "true" and "false".
If TAR_WARN is not set, or if it is set to "true",
then targets throws warnings in certain edge cases,
such as target/global name conflicts and dangerous use of
devtools::load_all(). If TAR_WARN is "false", then targets
does not throw warnings in these cases.
These warnings can detect potentially serious
issues with your pipeline, so please do not set TAR_WARN
unless your use case absolutely requires it.
See also
Other configuration:
tar_config_get(),
tar_config_projects(),
tar_config_set(),
tar_config_unset(),
tar_config_yaml(),
tar_option_get(),
tar_option_reset(),
tar_option_set()