repetitive path gives filename too long errors

[René J.V. Bertin]

Hello,

I'm struggling with the py-pykde4 package, which is giving me filename overflows due to constructing a path that contains repetitions of itself. I first ran into this in November, have since updated to CMake 3.1.2, and now see that the issue hasn't been solved:

https://mail.kde.org/pipermail/kde-mac/2014-November/002404.html

and that I'm not the only one:

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=750231

I saw a hint that using Ninja might avoid the issue, and indeed the cmake step works fine with that generator. However:

%> (cd py27-pykde4-mp9-work/build/ ; ninja)
/Volumes/Debian/MP9/var/macports/build/_Volumes_Debian_MP9_site-ports_python_py-pykde4/py27-pykde4/work/build
ninja: error: stat(_Volumes_Debian_MP9_var_macports_build__Volumes_Debian_MP9_site-ports_python_py-pykde4_py27-pykde4_work_build__Volumes_Debian_MP9_var_macports_build__Volumes_Debian_MP9_site-ports_python_py-pykde4_py27-pykde4_work_build__Volumes_Debian_MP9_var_macports_build__Volumes_Debian_MP9_site-ports_python_py-pykde4_py27-pykde4_work_build_pykdeconfig.pyc): File name too long
ninja: error: stat(CMakeFiles/_Volumes_Debian_MP9_var_macports_build__Volumes_Debian_MP9_site-ports_python_py-pykde4_py27-pykde4_work_build__Volumes_Debian_MP9_var_macports_build__Volumes_Debian_MP9_site-ports_python_py-pykde4_py27-pykde4_work_build__Volumes_Debian_MP9_var_macports_build__Volumes_Debian_MP9_site-ports_python_py-pykde4_py27-pykde4_work_build_pykdeconfig.pyc.util): File name too long
ninja: error: stat(CMakeFiles/_Volumes_Debian_MP9_var_macports_build__Volumes_Debian_MP9_site-ports_python_py-pykde4_py27-pykde4_work_build__Volumes_Debian_MP9_var_macports_build__Volumes_Debian_MP9_site-ports_python_py-pykde4_py27-pykde4_work_build__Volumes_Debian_MP9_var_macports_build__Volumes_Debian_MP9_site-ports_python_py-pykde4_py27-pykde4_work_build_pykdeconfig.pyc.util): File name too long
ninja: error: stat(CMakeFiles/_Volumes_Debian_MP9_var_macports_build__Volumes_Debian_MP9_site-ports_python_py-pykde4_py27-pykde4_work_build__Volumes_Debian_MP9_var_macports_build__Volumes_Debian_MP9_site-ports_python_py-pykde4_py27-pykde4_work_build__Volumes_Debian_MP9_var_macports_build__Volumes_Debian_MP9_site-ports_python_py-pykde4_py27-pykde4_work_build_pykdeconfig.pyc.util): File name too long
(etc)

Is this because of an error in pykde4's CMake files, or is this an unavoidable side-effect of the way CMake works?
NB: I tried setting pykde4_SOURCE_DIR and pykde4_BINARY_DIR on the commandline, but that had no effect (other than that the values appeared in CMakeCache.txt).

Thanks,
René