Hi tuskiomi,
The cygpath message is a known issue on master branch, it should be fixed if you pull the latest master:
https://github.com/espressif/esp-idf/issues/2839
(Although I don't think it's the cause of any build problems, it's just unnecessary messages in the log.)
There are some legitimate compiler errors in the output as well (found by searching for "error:"):
In file included from /home/brice/esp/hello_world/main/hello_world_main.c:23:0:
/home/brice/esp/hello_world/main/NetACP/AccessPoint.h:11:1: error: unknown type name 'class'
class AccessPoint {
(This is the first one, it keeps going from here down.)
It looks like you've included a C++ header file from a C file. You'll need to use a .cpp file to include C++ headers, the C compiler is used for .c files.
Probably this header and these lines will be underlined with red squiggles in the Eclipse editor as well, after the build finishes.