I get the following exception:

$ /opt/python3.0b2/bin/python3.0 -m trace -c -m run.py
Traceback (most recent call last):
  File "/opt/python3.0b2/lib/python3.0/runpy.py", line 121, in
_run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "/opt/python3.0b2/lib/python3.0/runpy.py", line 34, in _run_code
    exec(code, run_globals)
  File "/opt/python3.0b2/lib/python3.0/trace.py", line 809, in <module>
    main()
  File "/opt/python3.0b2/lib/python3.0/trace.py", line 806, in main
    results.write_results(missing, summary=summary, coverdir=coverdir)
  File "/opt/python3.0b2/lib/python3.0/trace.py", line 303, in write_results
    lnotab = find_executable_linenos(filename)
  File "/opt/python3.0b2/lib/python3.0/trace.py", line 428, in
find_executable_linenos
    return find_lines(code, strs)
  File "/opt/python3.0b2/lib/python3.0/trace.py", line 392, in find_lines
    linenos.update(find_lines(c, strs))
  File "/opt/python3.0b2/lib/python3.0/trace.py", line 386, in find_lines
    linenos = find_lines_from_code(code, strs)
  File "/opt/python3.0b2/lib/python3.0/trace.py", line 370, in
find_lines_from_code
    line_increments = [ord(c) for c in code.co_lnotab[1::2]]
  File "/opt/python3.0b2/lib/python3.0/trace.py", line 370, in <listcomp>
    line_increments = [ord(c) for c in code.co_lnotab[1::2]]
TypeError: ord() expected string of length 1, but int found

I think that line 370 of trace.py should say:

line_increments = [int(c) for c in code.co_lnotab[1::2]]

instead of:

line_increments = [ord(c) for c in code.co_lnotab[1::2]]

This can be further simplified:
   line_increments = code.co_lnotab[1::2]

Assigning to myself, I will try to add unit tests as well. the trace
module is not tested at all...

Here is a simple test suite for the trace module, and two corrections to 
make it work.

The test file is suitable for 2.6 (simply replace test.support with 
test.test_support)

Brett Cannon apparently fixed this in r69111 for 3.1.  I merged it to
the 30-maint branch in r73030.

It would be nice to add the tests, but they don't currently pass
(test_coverage_ignore fails).  I don't know if that's a test bug or a
code bug, not being familiar with the trace module.

Fixed the test cases and committed them in r83527.

TestCoverage.test_coverage_ignore fails when running in verbose mode ("python regrtest.py -v test_trace", or directly "python test_trace.py"), because it attempts to compare stdout.getvalue() with the empty string, while verbose places output there.

I will fix it as part of my merge with the larger test_trace.py for issue 9315.