When Jason van Brecht tried Walter Dnes's suggestion without success,
Philip Guenther wrote,
| The error message is being generated by xmessage, not procmail. I
| would guess that xmessage expects a filename as an argument and
| doesn't know to read stdin by default.
No, I get the same message,
programname: programname: cannot open
when procmail cannot execute programname, even though you'd logically expect
procmail: programname: cannot open
I had written privately to Jason that most likely xmessage is not in his
procmailrc's PATH (and he should fix the PATH, invoke xmessage by its
absolute path, or invoke xmessage by its relative path from $MAILDIR) or that
using it may require privileges that he has during his interactive logins but
which procmail processes started for him when he gets incoming mail do not
have. He did not reply.
Walter's recommendation to add a `c' flag is of value in keeping a copy in a
folder and also feeding it to xmessage, but it is not related to the problem
of being unable to execute xmessage.