rxvt-unicode extremely slow to start

[Richard Cobbe]

On Tue, Aug 23, 2016 at 09:19:24PM -0400, Richard Cobbe wrote:
> Some time within the last month or so, urxvt (from the rxvt-unicode
> package) has become very slow to start, taking on the order of 20 seconds
> to display the window after I launch it.  Once the window's up, everything
> works just fine: the shell or whatever program starts immediately, the
> window is responsive to user input, and the window disappears immediately
> after exiting the shell or whatever.
>
> I have no idea how to debug this.  Where should I look for information
> about what's going on?  I don't see anything in Console or under
> ~/LibraryLogs/X11.  Nothing's printed to stdout when I start urxvt from the
> shell prompt.  The only thing I've seen is that, according to htop, urxvt
> sits at about 100% CPU usage from the time when I launch the process until
> the window first appears.  Once the window becomes visible, the process's
> CPU usage drops back down to nothing.

Sorry; should have mentioned.  Other X clients start right up.

Richard