This trigger a bug:

Traceback (most recent call last):
  File "/home/ppepiot/src/hgview/hgviewlib/util.py", line 298, in <lambda>
    composed = lambda *args, **kwargs: f(g(*args, **kwargs))
  File "/home/ppepiot/src/hgview/hgviewlib/qt4/hgfileview.py", line 293, in displayFile
    except HgLookupError: # occur on deleted files
NameError: global name 'HgLookupError' is not defined


After the obvious NameError fix I get (on mercurial 5.0 and 5.1):

Traceback (most recent call last):
  File "/home/ppepiot/src/hgview/hgviewlib/util.py", line 298, in <lambda>
    composed = lambda *args, **kwargs: f(g(*args, **kwargs))
  File "/home/ppepiot/src/hgview/hgviewlib/qt4/hgfileview.py", line 300, in displayFile
    flag, data = self._model.graph.filedata(filename, self._ctx.rev(), mode)
  File "/home/ppepiot/src/hgview/hgviewlib/hggraph.py", line 608, in filedata
    parentctx = self.repo[self._fileparent(fctx)]
  File "/home/ppepiot/src/hgview/hgviewlib/hggraph.py", line 635, in _fileparent
    return fctx.p1().rev()
  File "/usr/lib/python2.7/dist-packages/mercurial/context.py", line 914, in p1
    return self.parents()[0]
  File "/usr/lib/python2.7/dist-packages/mercurial/context.py", line 1701, in parents
    pl = [(path, filenode(pcl[0], path), fl)]
  File "/usr/lib/python2.7/dist-packages/mercurial/context.py", line 1691, in filenode
    return ctx._manifest.get(path, nullid)
  File "/usr/lib/python2.7/dist-packages/mercurial/manifest.py", line 560, in get
    return self._lm[key][0]
TypeError: getitem: manifest keys must be a string.