UnboundLocalError: local variable 'city' referenced before assignment

[ojongerius]

Seen in logs (https://app.scrapinghub.com/p/247498/3/5/log?filterType=error&filterAndHigher) for do-it.org for url https://api.do-it.org/v2/opportunities?page=4

Traceback (most recent call last):
  File "/usr/local/lib/python3.6/site-packages/scrapy/utils/defer.py", line 102, in iter_errback
    yield next(it)
  File "/usr/local/lib/python3.6/site-packages/sh_scrapy/middlewares.py", line 30, in process_spider_output
    for x in result:
  File "/usr/local/lib/python3.6/site-packages/scrapy/spidermiddlewares/offsite.py", line 29, in process_spider_output
    for x in result:
  File "/usr/local/lib/python3.6/site-packages/scrapy/spidermiddlewares/referer.py", line 22, in <genexpr>
    return (_set_referer(r) for r in result or ())
  File "/usr/local/lib/python3.6/site-packages/scrapy/spidermiddlewares/urllength.py", line 37, in <genexpr>
    return (r for r in result or () if _filter(r))
  File "/usr/local/lib/python3.6/site-packages/scrapy/spidermiddlewares/depth.py", line 58, in <genexpr>
    return (r for r in result or () if _filter(r))
  File "/app/__main__.egg/vol/spiders/doit.py", line 41, in parse
    yield self.parse_job_page(job)
  File "/app/__main__.egg/vol/spiders/doit.py", line 64, in parse_job_page
    if city is None:
UnboundLocalError: local variable 'city' referenced before assignment