Installation fails due to conflicting tornado version

[NeolithEra]

Hi, users are unable to run gremlin-python-example due to dependency conflict with tornado package. As shown in the following full dependency graph of gremlin-python-example, gremlin-python-example requires tornado，while gremlinpython requires tornado>=4.4.1,<5.0.

According to pip’s “first found wins” installation strategy, tornado==6.0.3 is the actually installed version. However, tornado==6.0.3 does not satisfy tornado>=4.4.1,<5.0.

Dependency tree

gremlin-python-example-master
| +-gremlinpython(version range:*)
| | +-aenum(version range:>=1.4.5)
| | +-isodate(version range:>=0.6.0)
| | | +-six(version range:*)
| | +-six(version range:>=1.10.0)
| | +-tornado(version range:>=4.4.1,<5.0)
| +-tornado(version range:*)

Thanks for your help. Best, Neolith

[NeolithEra]

Solution

1. Fix your direct dependency to be tornado>=4.4.1,<5.0. I have checked this revision will not affect your downstream projects now.

2. Remove your direct dependency tornado, and use tornado transitively introduced by gremlinpython.

Which solution do you prefer, 1 or 2? @henzesberger Please let me know your choice. I can submit a PR to solve this issue.

[henzesberger]

Hi, I'm not the maintainer of this project, this question should go to @nedlowe.

I had a look and made some observations:

• The tornado library was checked into this project in the vendor folder and in Version 5, no idea why
• In the tests folder, the tornado library is not referenced so I guess it could completely be removed from requirements

BR, Hannes

[NeolithEra]

@henzesberger Thank you for your feedback.

@nedlowe Could help me review this issue?