With GDB 6.1, support for threads seems to be broken (not that I checked this functionality in earlier versions). When I run a multithreaded program such as Nautilus, I cannot switch to other threads nor even list them. gdb gets stuck with an error. (gdb) info threads 8 Thread 6151 (LWP 2875) Couldn't get registers: No such process. (gdb) thread 2 Couldn't get registers: No such process. (gdb) bt Couldn't get registers: No such process.
Unable to reproduce, please provide more information.
I run nautilus under gdb; I break (with Ctrl-C) when it freezes on actions described here: http://bugzilla.gnome.org/show_bug.cgi?id=139900 After that, 'info threads' results in the error. If I break execution outside of the hangup, 'info threads' proceeds without errors.
The problem should gone with update to gdb-6.6-alt1. Please reopen if not.