Have you tried to include the static library of the second project in Properties>C/C++ Build>Settings>Includes? If you do, does it make a difference?
Check how mraa is included there to guide you in how to include your library.
Thanks for your reply. The include does not change the issue. It is not surprising because I had added the library with its absolute path so there was no ambiguity there/
Also the error message refers to the absolute path of the library file.
I was reading about GCC and came accross a comment that in the Unix world GCCs add the prefix and the suffix automatically to the library name that is give with the -l option, Could it be the problem ? Would be strange that the Eclipse interface does not take that into account.
By the way what is strange is that there is no message about undefined symbols, which is the message I get if I omit to add the library. So clearly the library is accessed by the linker .. so I don't understand why LD complains it can't find it !
I found a work around:
Create the libXXXX.a archive as initially described.
Copy it in the folder : iotdk-ide-win\devkit-x86\sysroots\i586-poky-linux\usr\lib
In the project using the lib : Add the lib XXXX to the list in Properties>C/C++ General>Paths and Symbols>Libraries (! not libXXXX.a but just XXXX)
.. then all works out nicely