ok, i solved this problem but now when i run make i get another error
Generating test root file
/home/user/0ad/libraries/source/cxxtest-4.4/bin/cxxtestgen --root --include=precompiled.h --runner=ErrorPrinter -o /home/user/0ad/source/test_root.cpp
/usr/bin/env: "python": File or directory does not exist
make[1]: *** [cxxtestroot.make:36: ../../../binaries/system/cxxtestroot] Error 127
make: *** [Makefile:199: cxxtestroot] Error 2
EDIT:
For those who need: to fix the cxxtest build failed error run git status and then use git restore to add the missing paths that git status reported.