wpkg --make-tool ...
The --make-tool option defines the name of the make tool to use when building packages from source.
By default, the system uses make, which works under most environments. Under Unices, you may want to switch to gnumake:
wpkg --make-tool gnumake ...
Under MS-Windows, if you specified a cmake generator such as NMake Makefiles, then you will have to specify the make tool as in:
wpkg --make-tool nmake ...
Note that it is safe to explicitly set that option to the default: make.