i have encountered the known issue of 8192 characters limit for Windows command line during the build.
So i follow the proposed guide to solve it (Solving the 8192 Character Command Line Limit on Windows | MCU on Eclipse) but i have the same problem in another point of the build chain.
Before was make that cuts characters, now is the linker that removes slashes ( / ) from an include path.
I checked all paths in configurations and they are correct.
I tried to install different versions and installations of gnuarmeclipse-build-tools but the result is the same.
Temporarily i fixed moving project directory in root (C:) but what can i do to fix permanently the issue?
PS: i'm using Windows 8.1 Pro.
Could you post the log/output what the linker is doing?
Additionally, check that you have all needed tools updated. This is what I have in the 'bin' for 32bit:
And this what I have in the bin for 64bit Windows: