bash-3.2$ ddd `which virtuoso`
Warning: Cannot convert string "-*-fixed-bold-r-*-*-*-180-*-*-*-*-iso8859-*" to type FontStruct
(Annoyed?  Try 'Edit->Preferences->General->Suppress X Warnings'!)
Warning: XmStringGetNextComponent: unknown type 144475920

Warning: XmStringGetNextComponent: unknown type 144471904

ddd: xcb_xlib.c:41: xcb_xlib_lock: Assertion `!c->xlib.lock' failed.
Aborted
ddd: xcb_xlib.c:41: xcb_xlib_lock: Assertion `!c->xlib.lock' failed.

Internal error (Aborted).

Oops!  You have found a bug in DDD.

If you can reproduce this bug, please send a bug report
to <address@hidden>, giving a subject like

    DDD 3.3.11 (i386-redhat-linux-gnu) gets `Aborted' signal

To enable us to fix the bug, you should include the following information:
* What you were doing to get this message.  Report all the facts.
* The contents of the `~/.ddd/log' file as generated by this session.
Please read also the section "Reporting Bugs" in the DDD manual.

We thank you for your support.

ddd: xcb_xlib.c:41: xcb_xlib_lock: Assertion `!c->xlib.lock' failed.

Internal error (Aborted).

Oops!  You have found a bug in DDD.

If you can reproduce this bug, please send a bug report
to <address@hidden>, giving a subject like

    DDD 3.3.11 (i386-redhat-linux-gnu) gets `Aborted' signal

To enable us to fix the bug, you should include the following information:
* What you were doing to get this message.  Report all the facts.
* The contents of the `~/.ddd/log' file as generated by this session.
Please read also the section "Reporting Bugs" in the DDD manual.

We thank you for your support.

Aborted (core dumped)

bash-3.2$