Need to list minimum required tutor version

[throwaway-a]

Need to list minimum required tutor version

[fghaas]

If you need Tutor 12, you need to have tutor<13 somewhere in your own requirements list (however you express that), and then pip should be intelligent enough to install the prior version of the backup plugin, if both are installed in the same go.

I say "should" because we have run into pip resolver issues elsewhere (see hastexo/hastexo-xblock#216 if you're curious) where pip failed to do the right thing. But that's not something that the plugin can do anything about — as far as it is concerned, it is expressing its dependencies correctly. The latest version can only run with 13.2.0 or later, because that's when Tutor introduced the v2 plugin API, and as of version 0.1.0 this plugin is using that API.

That said, we never meant to support Tutor versions earlier than 13; we should probably have had that dependency in from the get-go, but unfortunately it's too late to retroactively do that now.

For what it's worth, this is what happens if you install with the latest pip at the time of writing (pip-22.1.2):

$ pip install "tutor<13" git+https://github.com/hastexo/[email protected]
Collecting git+https://github.com/hastexo/[email protected]
  Cloning https://github.com/hastexo/tutor-contrib-backup (to revision v0.1.0) to /tmp/pip-req-build-4367krue
  Running command git clone --filter=blob:none --quiet https://github.com/hastexo/tutor-contrib-backup /tmp/pip-req-build-4367krue
  Running command git checkout -q 3d3ea6fc13b69338d15b74adc30dfb8d14f34cd5
  Resolved https://github.com/hastexo/tutor-contrib-backup to commit 3d3ea6fc13b69338d15b74adc30dfb8d14f34cd5
  Preparing metadata (setup.py) ... done
Collecting tutor<13
  Using cached tutor-12.2.0-py3-none-any.whl
Collecting jinja2
  Using cached Jinja2-3.1.2-py3-none-any.whl (133 kB)
Collecting appdirs
  Using cached appdirs-1.4.4-py2.py3-none-any.whl (9.6 kB)
Collecting kubernetes
  Using cached kubernetes-24.2.0-py2.py3-none-any.whl (1.5 MB)
Collecting click>=7.0
  Using cached click-8.1.3-py3-none-any.whl (96 kB)
Collecting pycryptodome
  Using cached pycryptodome-3.15.0-cp35-abi3-manylinux2010_x86_64.whl (2.3 MB)
Collecting pyyaml>=4.2b1
  Using cached PyYAML-6.0-cp38-cp38-manylinux_2_5_x86_64.manylinux1_x86_64.manylinux_2_12_x86_64.manylinux2010_x86_64.whl (701 kB)
Collecting mypy
  Using cached mypy-0.961-cp38-cp38-manylinux_2_5_x86_64.manylinux1_x86_64.manylinux_2_12_x86_64.manylinux2010_x86_64.whl (17.8 MB)
INFO: pip is looking at multiple versions of <Python from Requires-Python> to determine which version is compatible with other requirements. This could take a while.
INFO: pip is looking at multiple versions of tutor to determine which version is compatible with other requirements. This could take a while.
Collecting tutor<13
  Using cached tutor-12.1.7-py3-none-any.whl
  Using cached tutor-12.1.6-py3-none-any.whl
  Using cached tutor-12.1.5-py3-none-any.whl
  Using cached tutor-12.1.4-py3-none-any.whl
  Downloading tutor-12.1.3.tar.gz (55 kB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 55.9/55.9 kB 460.0 kB/s eta 0:00:00
  Preparing metadata (setup.py) ... done
  Downloading tutor-12.1.2.tar.gz (55 kB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 55.8/55.8 kB 1.8 MB/s eta 0:00:00
  Preparing metadata (setup.py) ... done
  Downloading tutor-12.1.1.tar.gz (55 kB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 55.7/55.7 kB 2.1 MB/s eta 0:00:00
  Preparing metadata (setup.py) ... done
INFO: pip is looking at multiple versions of <Python from Requires-Python> to determine which version is compatible with other requirements. This could take a while.
INFO: pip is looking at multiple versions of tutor to determine which version is compatible with other requirements. This could take a while.
  Downloading tutor-12.1.0.tar.gz (55 kB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 55.7/55.7 kB 3.2 MB/s eta 0:00:00
  Preparing metadata (setup.py) ... done
  Downloading tutor-12.0.4.tar.gz (56 kB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 56.2/56.2 kB 1.8 MB/s eta 0:00:00
  Preparing metadata (setup.py) ... done
  Downloading tutor-12.0.3.tar.gz (56 kB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 56.1/56.1 kB 3.1 MB/s eta 0:00:00
  Preparing metadata (setup.py) ... done
  Downloading tutor-12.0.2.tar.gz (55 kB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 55.6/55.6 kB 2.4 MB/s eta 0:00:00
  Preparing metadata (setup.py) ... done
  Downloading tutor-12.0.1.tar.gz (56 kB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 56.3/56.3 kB 2.9 MB/s eta 0:00:00
  Preparing metadata (setup.py) ... done
INFO: This is taking longer than usual. You might need to provide the dependency resolver with stricter constraints to reduce runtime. See https://pip.pypa.io/warnings/backtracking for guidance. If you want to abort this run, press Ctrl + C.
INFO: This is taking longer than usual. You might need to provide the dependency resolver with stricter constraints to reduce runtime. See https://pip.pypa.io/warnings/backtracking for guidance. If you want to abort this run, press Ctrl + C.
ERROR: Cannot install tutor-contrib-backup==0.1.0 and tutor<13 because these package versions have conflicting dependencies.

The conflict is caused by:
    The user requested tutor<13
    tutor-contrib-backup 0.1.0 depends on tutor<14 and >=13.2.0

To fix this you could try to:
1. loosen the range of package versions you've specified
2. remove package versions to allow pip attempt to solve the dependency conflict

ERROR: ResolutionImpossible: for help visit https://pip.pypa.io/en/latest/topics/dependency-resolution/#dealing-with-dependency-conflict

In other words, with a current pip, nothing would have broken and pip would instead have prompted you to resolve the situation manually. If you're saddled with an ancient pip, it sadly only warns you about the version conflict but clobbers your installation anyway.