Environment variable CPPUTEST_HOME not working in some of the files when using docker

[Brac24]

In the first line where I run make in code-t2 I was initially getting an error of no directory found. At the bottom of the makefile in this directory there was an include $(CPPUTEST_HOME)/build/MakefileWorker.mk and it seemed that the CPPUTEST_HOME was not working properly. Just to test it out I replaced $(CPPUTEST_HOME) with ../cpputest/ and it worked but now it seems that the CPPUTEST_HOME gets called again to search for other files such as MemoryLeakDetectorNewMacros.h and as a result it won't build the tests.

This seems to be similar to pull request #9 but not sure what it can be.