Related to the errors I recived as I called the command "make -j5" in the gcc-directory of the 0ad-copy of alpha 0.0.23:
The content of the file buildRunner2.txt was:

Running cxxtest tests (2 tests).
In MyTestSuite2::testMultiplication:
MyTestSuite2.h:16: Error: Expected (2 * 2 == 5), found (4 != 5)
Failed 1 and Skipped 0 of 2 tests
Success rate: 50%

The to the last lines shortened console output was:

collect2: error: ld returned 1 exit status
pyrogenesis.make:83: recipe for target '../../../binaries/system/pyrogenesis' failed
make[1]: *** [../../../binaries/system/pyrogenesis] Error 1
Makefile:68: recipe for target 'pyrogenesis' failed
make: *** [pyrogenesis] Error 2