By default Ubuntu buildd's strip debug symbols and places them inddebs. To get a stack trace from attaching a local debugger you will need themlocally installed.

You can find the debug symbols that match your architecture and versionathttp://ddebs.ubuntu.com/ubuntu.You must install all 3 packages that match your architecture and version(libdfu1, libfwupd1, fwupd).

1. Add ddeb repository apt repository signing key

# wget -qO - http://ddebs.ubuntu.com/ubuntu/dbgsym-release-key.asc | sudo apt-key add -

2. Add the ddebs repository

# sudo add-apt-repository http://ddebs.ubuntu.com/ubuntu

3. Check for updates

# sudo apt update

3. Install debug symbols

# sudo apt install fwupd-dbgsym libdfu1-dbgsym libfwupd1-dbgsym

4. Follow the directions athttps://wiki.ubuntu.com/Backtrace#Already_running_programs to attach gdb to the fwupd process.