So, I just spent about 3 hours at work and at home debugging a small problem. I added functionality for a service bot to identify with the DrProject bot. This is done by the service bot sending IDENTIFY command to the DrProject bot, and waiting for a reply  “The operation succeeded”. Very simple concept, right?

INFO 2008-07-17T21:06:26 Received message from DrProjectBot: The operation succeeded.
error: “error:” is not a valid command.
error: “error:” is not a valid command.
error: “error:” is not a valid command.
error: “error:” is not a valid command.
INFO 2008-07-17T21:06:29 Ignoring *!DrProjectBot@127.0.0.1 for 600 seconds due to
an apparent invalid command flood.
WARNING 2008-07-17T21:06:29 Apparent error loop with another Supybot
observed.  Consider ignoring this bot permanently.

Basically, I didn’t RTFM. Every message received by a bot is interpreted as a command. So, when the service bot received “The operation succeeded.”, it was very angry at the DrProjectBot, because “The operation succeeded.” is not a valid command. It proceeded to yell at DrProjectBot with a message “error: “The” is not a valid command.”. Naturally, DrProjectBot also became angry, because “error: “The” is not a valid command.” is not a valid command, and the cycle started.

Thanks to good people on #supybot channel, I found a way for the bot to ignore non-command messages. Setting supybot.reply.whenNotCommand variable to False does the trick.