Warn: non-POSIX variable name

[Steven Woody]

Hi,


How do I remove these warnings when do automake:

    src/rmeterd/Makefile.am:9: shell ../../svndate-sh: non-POSIX variable name
    src/rmeterd/Makefile.am:9: (probably a GNU make extension)

in the Makefile.am, I did something like this:

    rmeterd_CXXFLAGS = \
                    -D'SVN_REV="$(shell ../../svnrev-sh)"' \
                    -D'SVN_DATE="$(shell ../../svndate-sh)"'

That is, I call a external shell script to get values that will be set
to a -D definition.

What's the correct way to do this without warning? Thanks.