How to build project files and packages for Borland C++ Builder 5 from the command line

c++buildercommand-line

How do I build Borland C++ project files (bpr) and package files (bpk) from the command line? Project groups (bpg) are apparently make files and can be compile with make. But bpks and bprs are xml based and the Export to Makefile won't compile with make.
If I put a project in a bpg, make can't seem to find any of the files specified in the bpg since they all appear to be relative references. I changed the references to absolutes and make reports:
Fatal: Unable to open makefile

Best Solution

You don't need to directly compile a bpr. Just create a bpk which just includes that single bpr, and you can use make to compile it.

"c:\program files\borland\cbuilder5\bin\make" -B -s -fabc.bpg

If you also have other borland compilers installed, do not call the make.exe from the other compiler.

EDIT: execute the make command in the directory where the bpg and bpr is located.