On my system (PC with Rewd Hat Linux), the installation fails when the headers
are copied into an include directory.
Exemple of typical failure:
gmake[1]: *** [includes] Error 2
/opt/geant/config/architecture.gmk:36: /etc/.mk:
No such file or directory

I have tried to track down the source of this problem, and it seems to be
related to the fact that the makefile tries to copy the header from the
subdirectory persistency even when this feature is not available and has not
been requested. In that case, HEP_ODBMS_DIR is not defined, and the line 36 of
architecture.gmk (include $(HEP_ODBMS_DIR)/etc/$(OS).mk) yields this error.

Possible fix (the one I used to bypass this problem):
change line 114 or source/GNUmakefile from

	@for dir in $(SUBDIR4); do (cd $$dir && $(MAKE) $@); done
to

ifdef G4USE_HEPODBMS
	@for dir in $(SUBDIR4); do (cd $$dir && $(MAKE) $@); done
endif