“thread apply all bt full” gives blank in GDB

Question

I was trying to debug a multi-threaded process on a Linux server running Slackware 12 using GDB 6.6.

Once I attach and issue the command "thread apply all bt full" it comes back with nothing ( back on to the gdb prompt ).

Any idea why this happens?

Answer 1

Try last GDB version. 7.1 or 7.2. Everything should work.

Answer 2

I ran into this problem and discovered that I can fix it as follows:

1. run "bt". this should show the backtrace of a thread, although maybe not the one you want.
2. now "cont".
3. hit ctrl+c. I see something like "[Switching to LWP %d]"
4. hit ctrl+c again. this breaks at the thread i want to see the backtrace of, but also seems to make "thread apply all bt full" start working.