Limit which environment variables are passed to a build step.

Environment variables passed to the build step are filtered, unless listed below.

The behavior of this filter depends on whether the environment variable is originally defined outside Jenkins:

- If the environment variable originates from Jenkins configuration, such as `JOB_URL` , it will not be passed to the build step unless specified here.
- If the environment variable originates from outside Jenkins, such as `PATH` , the behavior depends on the option Process environment variables handling : If that option is set to Retain , the original value will be passed to the build step, discarding any modifications inside Jenkins. If that option is set to Remove , the variable will not be passed to the build step.

The following table shows the effect of filtering on an environment variable:

Behavior | Originally defined outside Jenkins | Originally defined inside Jenkins
--- | --- | ---
Process environment variables handling: reset | Variable is reset to original value | Variable is removed
Process environment variables handling: removed | Variable is removed | Variable is removed