Funny wise, I came to the Idea, to delete the uncompressed directory and uncompress again. The result of going in the directory "0ad-0.0.23-alpha/build/workspaces" calling the script with "./update-workspaces.sh --with-system-nvtt -j5" going into the subdirectory gcc and calling "make -j5" did throw a lesser number of error messages. Only these messages kept remained, after many status messages :
==== Building pyrogenesis (release) ====
main.cpp
Linking pyrogenesis
../../../binaries/system/libengine.a(ModIo.o): In function `ModIo::ModIo()':
/home/arne/0ad_Ken_Wood/0ad-0.0.23-alpha/build/workspaces/gcc/../../../source/ps/ModIo.cpp:120: undefined reference to `sodium_base642bin'
../../../binaries/system/libengine.a(ModIo.o): In function `ModIo::ParseSignature(std::vector<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > const&, SigStruct&, PKStruct const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&)':
/home/arne/0ad_Ken_Wood/0ad-0.0.23-alpha/build/workspaces/gcc/../../../source/ps/ModIo.cpp:777: undefined reference to `sodium_base642bin'
/home/arne/0ad_Ken_Wood/0ad-0.0.23-alpha/build/workspaces/gcc/../../../source/ps/ModIo.cpp:793: undefined reference to `sodium_base642bin'
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"
Okay it are not so much as before, but I must agree that I'm confused now. Especially what I entered wrong things before.