This was an issue we've been dealing with for a while now - we're building a C++ project using the Cygwin toolchain, and no matter what we add in the C++ compiler include paths under project settings, Eclipse can't seem to find the necessary header files.
We have done everything the Stackoverflow community has suggested so far;
- Made sure include paths were workspace-relative
- Tried backslashes and forward slashes
- Tried using Cygwin-specific paths (/cygdrive/c instead of C:/)
- Checked the compiler output to verify include paths are there
- Checked the generated makefiles to make sure they're correct
- Rebuilt the index
- Deleted the debug folder entirely
- restarted Eclipse
Basically nothing short of changing the #include <...> code itself to use a full path (C:/.../file.h) worked. This doesn't work for our needs as we need multiple developers to be able to work on this project, and the files themselves are generated dynamically as a result of some of our build procedures.