Conflicts between scrapy-qtwebkit and Twisted

[NeolithEra]

Hi, users are unable to run scrapy-qtwebkit due to dependency conflict with Twisted package.

As shown in the following full dependency graph of scrapy-qtwebkit, scrapy-qtwebkit requires Twisted>=18，while Scrapy 1.7.2 requires _Twisted>=13.1.0; python_version!="3.4"', 'Twisted>=13.1.0,<=19.2.0; python_version=="3.4"_.

According to pip’s “first found wins” installation strategy, Twisted==19.2.1 is the actually installed version. However, Twisted==19.2.1 does not satisfy Twisted>=13.1.0,<=19.2.0.

Dependency tree--------

scrapy-qtwebkit-master
| +-Twisted(version range:>=18)
| +-Scrapy(version range:>=1.5)
| | +-Twisted(version range:>=13.1.0python_version!="3.4")
| | +-Twisted(version range:>=13.1.0,<=19.2.0python_version=="3.4")
| | +-w3lib(version range:>=1.17.0)
| | +-queuelib(version range:*)
| +-qt5reactor(version range:==0.5)

Thanks for your help. Best, Neolith

[NeolithEra]

Solution

Remove your direct dependency Twisted, and use the Twisted transitively introduced by Scrapy.

@ArturGaspar May I pull a request to fix this issue?

[ArturGaspar]

Thanks for reporting this. Please do make the pull request.

Instead of removing the dependency altogether, does it make sense to depend on Twisted>=18,<=19.2.0?