archcheck portgroup explodes if "port" prints a generic error

[ryandesign (Ryan Carsten Schmidt)]

If the "port" command would print an error regardless what command you use (e.g. "Warning: More than one default port source is defined." or "Warning: port definitions are more than two weeks old, consider using selfupdate"), the archcheck portgroup's error display fails, e.g.:

--->  Configuring ghc
DEBUG: Using compiler 'Mac OS X gcc 4.2'
DEBUG: Executing proc-pre-org.macports.configure-configure-0
Error: Target org.macports.configure returned: /opt/local/lib/libgmp.dylib is provided by: gmp
Warning: More than one default port source is defined.
DEBUG: Backtrace: /opt/local/lib/libgmp.dylib is provided by: gmp
Warning: More than one default port source is defined.
    while executing
"$pre $targetname"
Warning: the following items did not execute (for ghc): org.macports.configure
Error: Status 1 encountered during processing.
To report a bug, see <http://guide.macports.org/#project.tickets>

[jmroot (Joshua Root)]

ui_warn goes to stderr so you should be able to separate warnings from the actual output.

[ryandesign (Ryan Carsten Schmidt)]

Yes indeed, just throwing away the stderr fixes it. r64361.