How to force an error in a gnumake file

Question

I want to detect a condition in my makefile where a tool is the wrong version and force the make to fail with an error message indicating the item is not the right version.<

Answer 1

The conditional needs some attention too.

ifeq ($(shell svnversion --version | sed s/[^0-9\.]*://), 1.4) 
    $(error Bad svnversion v1.4, please install v1.6)
endif