CUDA SDK issues with gcc/g++: old version of gcc can't find old version of g++?

Question

I'm installing CUDA on F15. I'm well aware of the fact CUDA needs older versions gcc/g++ and I've installed gcc/g++ 4.5.1, and softlinked them as documented here . I no longer get the error mentioned in that post...however, when I tried compiling the SDK, I get the following error:

make[1]: Entering directory `/home/whao/NVIDIA_GPU_Computing_SDK/C/src/bilateralFilter'
gcc: error trying to exec 'cc1plus': execvp: No such file or directory
make[1]: *** [obj/x86_64/release/filter_kernel.cu.o] Error 1

I suspect that somehow, the older version of g++ in question isn't being recognized? For what it's worth, consider the following two outputs:

[whao@gen-whao-cuda C]$ /usr/local/cuda/bin/gcc --version
gcc (GCC) 4.5.1 20101130 (Red Hat 4.5.1-6)
Copyright (C) 2010 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[whao@gen-whao-cuda C]$ /usr/local/cuda/bin/g++ --version
g++ (GCC) 4.5.1 20101130 (Red Hat 4.5.1-6)
Copyright (C) 2010 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Answer 1

There is a file named host_config.h where gcc version is checked (the path is /usr/local/cuda/include). You can comment out the appropriate if part (if gcc_version>4.5.* ....). gcc 4.5 may be supported in toolkit 4.1 but if this lines remain, there always be an error before even start compiling.