+2  A: 
Beta
Full points for '1.'. I would like the contents of svn-version.mk to be persistent: its used as a reference point since the last version the log output was created. i.e. take log messages between the last time run and now: "svn -log $(SVN_VERSION):HEAD > log.txt; ~redo svn-version.mk~"
Jamie
I'm not going for a POSIX make; and I'm taking advantage of the conditional include provided by GNU make. In fact, I didn't create a specific rule for 'svn-version.mk, instead it's a side-affect/additional output of the 'release' target itself. If I made svn-version.mk a prerequisite then I would get the behaviour you describe. I hope my 'solution' above illuminates what I was trying to do.
Jamie