The AR was invoked as:
/usr/bin/ar rcu ./Debug/libstmass.a @"stmass.txt"
reason:
ar: @stmass.txt: No such file or directory
Where to remove @ (AT char) ? In makefile it does not make sense.
All this was done on Mac OS X 10.9
does not help the option is checked always.settings->build settings->compilers-
select your compiler form the list on the left side, and switch to the 'Advanced' tab
Uncheck the option: "Pass object list to the linker via file"