We're trying to get clang++ working in a chroot directory, and
currently it's not finding any of the g++ include dirs, e.g.
/usr/include/c++/4.8. How does it find those? Does it invoke g++?
Is there any way to get more information about what's going wrong?
I think the paths are in ToolChains.cpp and InitHeaderSearch.cpp depending on the OS.
Search for “/usr/” to find more maybe-relevant sources.
Running clang with "-v" and some input file should print some info
about which directories it's looking at, which can be useful for
debugging this kind of thing.