Re: bug (feature?) in zsh

[Bart Schaefer <schaefer@brasslantern.com>]

On Jan 16,  2:16am, Toshiro wrote:
} Subject: bug (feature?) in zsh
}
} I'm using Debian unstable, zsh version 4.2.2. I've noticed that, when I 
} install a new package that puts some program in my path (for 
} example, /usr/bin) I can't invoke the program using completion in any zsh 
} shell that I have opened before installing the program. 

This is almost reaching FAQ status, but isn't yet in the FAQ.

The completion system (including compctl) uses the command hash table to
look up names for completion in command position, because it's expensive
to search the path for them.  That means that if you install some new
piece of software, you need to run 'rehash' before the completion system
will see it, as you discovered.

See the zsh-users thread with subject "HASH_LIST_ALL?" from October 2004
for more discussion; in particular, article 8059 presents a technique
for working around this behavior.