I have found myself needing to go through the complicated shell sequence for the $(RECURSIVE_TARGETS) rule more than once when debugging the Makefile.am's in a big directory tree (namely TeX Live). Typically I get a mysterious "*** failed", exit status 1, and there's no easy way to know which command failed.
I'd like to suggest that that initial silencing "@" become a variable, say RECURSIVE_TARGET_VERBOSE. Of course the default would still be @, but then it could easily be overridden with, say, "set -vx;", to at least help narrow down the point of failure. Wdyt? Thanks, Karl