libEnv.Tool('addLinkDeps', package='myPackage', toBuild='shared')
myLib = libEnv.SharedLibrary('myPkgLib', listFiles('src/*.cxx'))
swigEnv.Tool('addLinkDeps', package='myPackage', toBuild='swig')
mySwigWrapper = swigEnv.SwigLibrary('_py_myPkgLib', 'src/py_myPkg.i')
# More lines defining apps, test programs, etc. Then register:
....
progEnv.Tool('registerTargets', package = 'myPackage',
libraryCxts = [[myLib, libEnv]],
swigCxts = [[mySwigWrapper, swigEnv]],
includes = ... )