(gdb) run
Starting program: /usr/bin/scantool 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib/libthread_db.so.1".
scantool: Interface set to default: CARSIM on /dev/null
scantool: freediag version 1.06
scantool: Type HELP for a list of commands
scantool: Type SCAN to start ODBII Scan
scantool: Then use MONITOR to monitor real-time data
scantool: **** IMPORTANT : this is beta software ! Use at your own risk.
scantool: **** Remember, "debug all -1" displays all debugging info.
interface is now MET16 on /dev/ttyUSB0
scantool: Settings loaded from /root/.freediagrc

scantool> scan

Trying SAEJ1850-VPW:
clock_gettime(): using CLOCK_MONOTONIC_RAW
clock_nanosleep(): using CLOCK_MONOTONIC
diag_os_gethrt() resolution <= 0us, avg ~0us
diag_os_getms() resolution <= ~1ms, avg ~1ms
testing diag_os_millisleep(), this will take a moment...
diag_os_chronoms() : initial time 1457587757443ms; resolution: ~1ms
[New Thread 0x7ffff7ff7700 (LWP 19066)]

Thread 1 "scantool" received signal SIGUSR1, User defined signal 1.
0x00007ffff73bbc0d in read () from /usr/lib/libc.so.6
(gdb) step
Single stepping until exit from function read,
which has no line number information.
[New Thread 0x7ffff6e56700 (LWP 19067)]

Thread 3 "scantool" received signal SIGUSR1, User defined signal 1.
[Switching to Thread 0x7ffff6e56700 (LWP 19067)]
0x00007ffff7686c5a in ?? () from /usr/lib/librt.so.1
(gdb) step
Cannot find bounds of current function
(gdb)