Environment variables defined here will be made available to every build executed by this agent, and will override any environment variables that have the same Name as those defined on the Configure System page.

Using the syntax `$NAME` or `${NAME}` (`%NAME%` on Windows), these variables can be used in job configurations, or from process launched by a build.

Jenkins also supports a special syntax, `BASE+EXTRA`, which allows you to add multiple key-value pairs here, which will be prepended to an existing environment variable.

For example, if you have a machine which has `PATH=/usr/bin`, you could add to the standard path by defining an environment variable here, with the name `PATH+LOCAL_BIN` and value `/usr/local/bin`.
This would result in `PATH=/usr/local/bin:/usr/bin` being exported during builds executed on this machine. `PATH+LOCAL_BIN=/usr/local/bin` will also be exported.
Multiple entries are prepended to the "base" variable according to the alphabetical order of the "extra" part of the name.

If the Value is empty or whitespace-only, it will not be added to the environment, nor will it override or unset any environment variable with the same name that may already exist (e.g. a variable defined by the system).