It is only in CVS HEAD of CMake at this point, but you may consider using
the new function add_external_project (in Modules/AddExternalProject.cmake)
for this purpose. There is example usage in the CMake source tree at
CMake/Tests/ExternalProject/CMakeLists.txt.
It will eventually be released in
As I ponder moving our entire hairy system to cmake, I'm stuck with several
sub-projects where I will not want to replace the existing build system. In
particular we use internal builds of several FSF tools and when necessary to
build one as part of building a cmake'd project we'll just want to
