[Bug 1834379] Re: armhf Bionic python3-pygraphviz package errors for simple use case

[Didier Roche]

** Also affects: python-pygraphviz (Ubuntu Eoan)
   Importance: Undecided
       Status: New

** Also affects: python-pygraphviz (Ubuntu Bionic)
   Importance: Undecided
       Status: New

** Also affects: python-pygraphviz (Ubuntu Disco)
   Importance: Undecided
       Status: New

** Also affects: python-pygraphviz (Ubuntu Cosmic)
   Importance: Undecided
       Status: New

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Title:
  armhf Bionic python3-pygraphviz package errors for simple use case

Status in python-pygraphviz package in Ubuntu:
  New
Status in python-pygraphviz source package in Bionic:
  New
Status in python-pygraphviz source package in Cosmic:
  New
Status in python-pygraphviz source package in Disco:
  New
Status in python-pygraphviz source package in Eoan:
  New

Bug description:
  [Impact]

  python3-pygraphviz does not work for even simple use cases on armhf
  Bionic. See error output in Test Case section from adding an edge to a
  graph.

  This package is currently being used as a dependency of ROS2, which is
  now including armhf as a target platform. The functionality that
  depends on this package fails to run.

  Conclusion from below testing is that the current package is somehow
  corrupted.

  A no-change rebuild in ppa:emersonknapp/ppa works properly on armhf.

  [Test Case]

  Using the following test file, and running python3 test.py, the
  program raises an error. However program exits with no output as
  expected on x86_64 and aarch64

  ```
  # test.py
  #!/usr/bin/env python3

  import pygraphviz

  graph = pygraphviz.AGraph()
  graph.add_node('foo')
  graph.add_node('bar')
  graph.add_edge('foo', 'bar')
  ```

  Error seen

  ```
  Traceback (most recent call last):
    File "/usr/lib/python3/dist-packages/pygraphviz/agraph.py", line 1561, in __new__
      nh = gv.agnode(graph.handle, n.encode(graph.encoding), _Action.find)
  KeyError: 'agnode: no key'

  During handling of the above exception, another exception occurred:

  Traceback (most recent call last):
    File "test.py", line 8, in <module>
      graph.add_edge('foo', 'bar')
    File "/usr/lib/python3/dist-packages/pygraphviz/agraph.py", line 478, in add_edge
      e = Edge(self, eh=eh)
    File "/usr/lib/python3/dist-packages/pygraphviz/agraph.py", line 1625, in __new__
      s = Node(graph, nh=source)
    File "/usr/lib/python3/dist-packages/pygraphviz/agraph.py", line 1563, in __new__
      raise KeyError("Node %s not in graph." % n)
  KeyError: 'Node None not in graph.'
  ```

  [Regression Potential]

  This is a no-change rebuild, regression potential is very low.

  [Other Info]

  If I upgrade to 1.5 via pip after installing the apt dependency
  libgraphviz-dev, this same snippet works on all of these platforms.

  It also works if I install pygraphviz 1.4rc1 from pip. Also, it seems
  to work with the debian package python3-pygraphviz 1.4 from cosmic. As
  far as I can tell, there are no differences between the cosmic and the
  bionic packages, other than it was rebuilt for Python 3.7.

  Here's a summary:

  Bionic	1.4~rc1	Debian	Broken
  Cosmic	1.4~rc1	Debian	Works
  Disco	1.5	Debian	Works
  Bionic	1.4~rc1	pip	Works
  Bionic	1.5	pip	Works

  And one more data point; if I pull down the debian sources (apt-get
  source python3-pygraphviz ; apt-get build-dep python3-pygraphviz),
  build with no modifications (debuild -uc -us), and then install (dpkg
  -i python3-pygraphviz_1.4~rc1-1build2_armhf.deb), it works just fine.

  From all of this, I can only conclude that the Ubuntu Bionic armhf
  debian package is somehow corrupt. Perhaps a rebuild of the package
  would solve the problem.

  ProblemType: Bug
  DistroRelease: Ubuntu 18.04
  Package: python3-pygraphviz 1.4~rc1-1build2
  ProcVersionSignature: Ubuntu 4.15.0-1041.43-aws 4.15.18
  Uname: Linux 4.15.0-1041-aws aarch64
  ApportVersion: 2.20.9-0ubuntu7.6
  Architecture: armhf
  Date: Wed Jun 26 22:23:47 2019
  ProcEnviron:
   TERM=xterm
   PATH=(custom, no user)
   LANG=en_US.UTF-8
  SourcePackage: python-pygraphviz
  UpgradeStatus: No upgrade log present (probably fresh install)

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