GDB hang on "run"

Hi,
Lately gdb has been hanging for me when running my executable. I'm using
GDB 8.1 but it occurs with older versions as well. Here's what I see:

(gdb) source run.gdb
Temporary breakpoint 1 at 0xbaf645: file <path>/<file>.cc, line 3501.
^CTraceback (most recent call last):
  File "/<path>/gcc-6.2.0/redhat6/lib64/libstdc++.so.6.0.22-gdb.py", line
18, in <module>
    import gdb
ImportError: No module named gdb

What I see is a hang right before the Traceback message, that's only
bypassed by sending a SIGINT. Anyone know why this might be and what I can
do to avoid it? Or tips on how to debug this problem?

Thanks,
Uri