Why does grep [^0-9] become grep u?

[David Liontooth]

In two windows of the same KDE konsole, I get this:

$ echo aa | strace grep [^0-9]
execve("/bin/grep", ["grep", "u"], [/* 31 vars */]) = 0

$ echo aa | strace grep [^0-9]
execve("/bin/grep", ["grep", "[^0-9]"], [/* 31 vars */]) = 0

Something on my system got reset -- any new terminal I open interprets
[^0-9] as u.  What's going on?

Dave


grep                    2.5.1.ds2-6

Debian sid amd64