segmentation fault on Ubuntu 12.04

As a new user of GNU radio with a couple RTL2832 dongles to play with I used the build-gnuradio script to install on Fedora 16 and Ubuntu 12.04. The Fedora install worked fine; but the Ubuntu one produced this: lemur4[18]$ rtl_test Found 1 device(s): 0: ezcap USB 2.0 DVB-T/DAB/FM dongle Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle Found Elonics E4000 tuner Supported gain values (14): -1.0 1.5 4.0 6.5 9.0 11.5 14.0 16.5 19.0 21.5 24.0 29.0 34.0 42.0 Reading samples in async mode... cb transfer status: 1, canceling... Library error 0, exiting... Segmentation fault (core dumped) The traceback showed the fault to occur in libusb1, and seemed similar to the issue discussed at http://lists.gnumonks.org/pipermail/osmocom-sdr/2012-August/000201.html I noticed this patch at the head of master touched the same general part of the code. commit 3cbf1392612a0c6f02ec178f8e78568138f12b0a Author: Hoernchen <la(a)tfc-server.de> Date: Wed Jan 16 20:03:00 2013 +0100 exit if our usb device disappears Reverting this change fixed the issue. Peter