Trace result formatter crashes

[mfeit-internet2]

Probably passing a wrong value somewhere.

$ pscheduler task trace --dest psmp-gn-bw-bud-hu.geant.org
...
Problem fetching results: Failed to format result: Traceback (most recent call last):
  File "/usr/libexec/pscheduler/classes/test/trace/result-format", line 69, in <module>
    pscheduler.result_format_method(TEMPLATE, max_schema=MAX_SCHEMA, validator=result_is_valid)
  File "/usr/lib/python3.9/site-packages/pscheduler/text.py", line 272, in result_format_method
    return _format_method(template,
  File "/usr/lib/python3.9/site-packages/pscheduler/text.py", line 251, in _format_method
    succeed(jinja2_format(template, json_stripped, strip=True))
  File "/usr/lib/python3.9/site-packages/pscheduler/text.py", line 171, in jinja2_format
    finished = j2.from_string(HEADER + template).render(info)
  File "/usr/lib/python3.9/site-packages/jinja2/environment.py", line 1090, in render
    self.environment.handle_exception()
  File "/usr/lib/python3.9/site-packages/jinja2/environment.py", line 832, in handle_exception
    reraise(*rewrite_traceback_stack(source=source))
  File "/usr/lib/python3.9/site-packages/jinja2/_compat.py", line 28, in reraise
    raise value.with_traceback(tb)
  File "<template>", line 17, in top-level template code
  File "/usr/lib/python3.9/site-packages/pscheduler/text.py", line 148, in iso8601_duration_seconds_helper
    delta = iso8601_as_timedelta(duration)
  File "/usr/lib/python3.9/site-packages/pscheduler/iso8601.py", line 15, in iso8601_as_timedelta
    duration = isodate.parse_duration(iso)
  File "/usr/lib/python3.9/site-packages/isodate/isoduration.py", line 86, in parse_duration
    raise TypeError("Expecting a string %r" % datestring)
TypeError: Expecting a string Undefined

Result that caused this:

{
  "paths": [
    [
      {
        "ip": "10.88.0.1",
        "rtt": "P0D",
        "hostname": "host.containers.internal"
      },
      {
        "ip": "10.0.2.2",
        "rtt": "PT0.0002S"
      },
      {},
      {
        "as": {
          "owner": "MERIT-AS-14, US",
          "number": 237
        },
        "ip": "192.122.200.73",
        "rtt": "PT0.0019S",
        "hostname": "xe-11-0-1x241.sfld-cor-123net.mich.net"
      },
      {
        "as": {
          "owner": "MERIT-AS-14, US",
          "number": 237
        },
        "ip": "192.122.183.10",
        "rtt": "PT0.007S",
        "hostname": "v0x1004.rtr.wash.net.internet2.edu"
      },
      {
        "ip": "163.253.1.174",
        "rtt": "PT0.0168S",
        "hostname": "fourhundredge-0-0-0-3.4079.core2.clev.net.internet2.edu"
      },
      {
        "ip": "163.253.1.138",
        "rtt": "PT0.017S",
        "hostname": "fourhundredge-0-0-0-3.4079.core2.ashb.net.internet2.edu"
      },
      {
        "ip": "163.253.1.121",
        "rtt": "PT0.0166S",
        "hostname": "fourhundredge-0-0-0-1.4079.core1.wash.net.internet2.edu"
      },
      {
        "as": {
          "owner": "GEANT The GEANT IP Service, NL",
          "number": 20965
        },
        "ip": "62.40.124.44",
        "rtt": "PT0.0973S",
        "hostname": "internet2.mx1.lon.uk.geant.net"
      },
      {
        "as": {
          "owner": "GEANT The GEANT IP Service, NL",
          "number": 20965
        },
        "ip": "62.40.98.22",
        "rtt": "PT0.102S",
        "hostname": "ae4.rt1.ams.nl.geant.net"
      },
      {
        "as": {
          "owner": "GEANT The GEANT IP Service, NL",
          "number": 20965
        },
        "ip": "62.40.98.21",
        "rtt": "PT0.1088S",
        "hostname": "ae8.rt1.fra.de.geant.net"
      },
      {
        "as": {
          "owner": "GEANT The GEANT IP Service, NL",
          "number": 20965
        },
        "ip": "62.40.98.159",
        "rtt": "PT0.1152S",
        "hostname": "ae6.rt1.pra.cz.geant.net"
      },
      {
        "as": {
          "owner": "GEANT The GEANT IP Service, NL",
          "number": 20965
        },
        "ip": "62.40.98.243",
        "rtt": "PT0.1197S",
        "hostname": "ae5.mx1.vie.at.geant.net"
      },
      {
        "as": {
          "owner": "GEANT The GEANT IP Service, NL",
          "number": 20965
        },
        "ip": "62.40.98.44",
        "rtt": "PT0.1243S",
        "hostname": "ae3.mx1.bud.hu.geant.net"
      },
      {
        "as": {
          "owner": "GEANT The GEANT IP Service, NL",
          "number": 20965
        },
        "ip": "62.40.114.47",
        "rtt": "PT0.1231S",
        "hostname": "psmp-gn-bw-bud-hu.geant.org"
      }
    ]
  ],
  "schema": 1,
  "succeeded": true
}

[mfeit-internet2]

Wasn't handling no-response hops. Fixed.