Code review comment for lp:~jba-aps/epics-base/dbdcat

RULES.Db has a commented-out line in the rule for $(COMMON_DBDCATS):$(COMMON_DIR)/%.dbd which looks like you probably didn't mean to leave it there.

Should dbdExpand print an error message when it gets run with no input files to expand? I think we should try to make it as easy as we can for users to understand what they did wrong when this happens, even though the build will fail immediately afterwards anyway with this code. I would like dbdExpand to exit with an error status in this case as well (causing GNUmake to stop immediately), so instead of exit 0 I suggest using die with a suitable message string (that ends in a newline to suppress the line-number that Perl will append to it otherwise). The message should include the name of the DBD file it was being asked to create.