You can also add commands to the prototype file of the form !PARAM=value. Commands of this form define variables in the current environment. If you have multiple prototype files, the scope of this command is local to the prototype file where it is defined.
The variable PARAM can begin with either a lowercase letter or an uppercase letter. If the value of the PARAM variable is not known at build time, the pkgmk command aborts with an error. For more information on the difference between build variables and install variables, see Package Environment Variables.