A description of an individual environment variable and how it should be applied to the current environment to produce the environment for the containing build, make or job.
Name of the environment variable.
Type of environment update represented by this entry. One of add, modify, or delete. The default value is add, which means that the variable should be added to the environment with the given value. modify means that the variable’s value should be replaced with the given value. delete means that the variable should be removed from the environment.