readthedocs.org: pip install killed due to excessive memory consumption (due to new pip resolver)

Details

I have opened this issue on pip itself (https://github.com/pypa/pip/issues/9318) but I’m opening it here as well, to track its progress, since it is only on RTD that I have encountered it, and I’m sure I will not be the only RTD user affected by this. Also perhaps there may be an RTD specific aspect to the fix.

Example RTD build: https://readthedocs.org/projects/markdown-it-py/builds/12576084/

Collecting attrs<21,>=19
  Downloading attrs-20.3.0-py2.py3-none-any.whl (49 kB)
Collecting mdit-py-plugins~=0.2.1
  Downloading mdit_py_plugins-0.2.1-py3-none-any.whl (38 kB)
Collecting myst-nb~=0.10.0
  Downloading myst_nb-0.10.1-py3-none-any.whl (36 kB)
Collecting docutils>=0.15
  Downloading docutils-0.16-py2.py3-none-any.whl (548 kB)
Collecting ipywidgets<8,>=7.0.0
  Downloading ipywidgets-7.5.1-py2.py3-none-any.whl (121 kB)
Collecting ipykernel>=4.5.1
  Downloading ipykernel-5.4.2-py3-none-any.whl (119 kB)
Collecting ipython
  Downloading ipython-7.19.0-py3-none-any.whl (784 kB)
Requirement already satisfied: pygments in /home/docs/checkouts/readthedocs.org/user_builds/markdown-it-py/envs/98/lib/python3.7/site-packages (from ipython->myst-nb~=0.10.0->markdown-it-py==0.6.0) (2.7.3)
Requirement already satisfied: setuptools>=18.5 in /home/docs/checkouts/readthedocs.org/user_builds/markdown-it-py/envs/98/lib/python3.7/site-packages (from ipython->myst-nb~=0.10.0->markdown-it-py==0.6.0) (41.0.1)
Collecting jedi>=0.10
  Downloading jedi-0.17.2-py2.py3-none-any.whl (1.4 MB)
Collecting jupyter-cache~=0.4.1
  Downloading jupyter_cache-0.4.1-py3-none-any.whl (31 kB)
Collecting jupyter-sphinx~=0.3.1
  Downloading jupyter_sphinx-0.3.2-py3-none-any.whl (20 kB)
Collecting myst-parser~=0.12.9
  Downloading myst_parser-0.12.10-py3-none-any.whl (34 kB)
  Downloading myst_parser-0.12.9-py3-none-any.whl (34 kB)
INFO: pip is looking at multiple versions of jupyter-sphinx to determine which version is compatible with other requirements. This could take a while.
Collecting jupyter-sphinx~=0.3.1
  Downloading jupyter_sphinx-0.3.1-py3-none-any.whl (19 kB)
INFO: pip is looking at multiple versions of jupyter-cache to determine which version is compatible with other requirements. This could take a while.
INFO: pip is looking at multiple versions of jedi to determine which version is compatible with other requirements. This could take a while.
Collecting jedi>=0.10
  Downloading jedi-0.17.1-py2.py3-none-any.whl (1.4 MB)
  Downloading jedi-0.17.0-py2.py3-none-any.whl (1.1 MB)
  Downloading jedi-0.16.0-py2.py3-none-any.whl (1.1 MB)
INFO: pip is looking at multiple versions of jupyter-sphinx to determine which version is compatible with other requirements. This could take a while.
  Downloading jedi-0.15.2-py2.py3-none-any.whl (1.1 MB)
  Downloading jedi-0.15.1-py2.py3-none-any.whl (1.0 MB)
  Downloading jedi-0.15.0-py2.py3-none-any.whl (1.0 MB)
INFO: This is taking longer than usual. You might need to provide the dependency resolver with stricter constraints to reduce runtime. If you want to abort this run, you can press Ctrl + C to do so. To improve how pip performs, tell us what happened here: https://pip.pypa.io/surveys/backtracking
  Downloading jedi-0.14.1-py2.py3-none-any.whl (1.0 MB)
INFO: pip is looking at multiple versions of jupyter-cache to determine which version is compatible with other requirements. This could take a while.
INFO: pip is looking at multiple versions of jedi to determine which version is compatible with other requirements. This could take a while.
  Downloading jedi-0.14.0-py2.py3-none-any.whl (1.0 MB)
  Downloading jedi-0.13.3-py2.py3-none-any.whl (178 kB)
  Downloading jedi-0.13.2-py2.py3-none-any.whl (177 kB)
  Downloading jedi-0.13.1-py2.py3-none-any.whl (177 kB)
  Downloading jedi-0.13.0-py2.py3-none-any.whl (177 kB)
INFO: This is taking longer than usual. You might need to provide the dependency resolver with stricter constraints to reduce runtime. If you want to abort this run, you can press Ctrl + C to do so. To improve how pip performs, tell us what happened here: https://pip.pypa.io/surveys/backtracking
INFO: This is taking longer than usual. You might need to provide the dependency resolver with stricter constraints to reduce runtime. If you want to abort this run, you can press Ctrl + C to do so. To improve how pip performs, tell us what happened here: https://pip.pypa.io/surveys/backtracking
  Downloading jedi-0.12.1-py2.py3-none-any.whl (174 kB)
  Downloading jedi-0.12.0-py2.py3-none-any.whl (172 kB)
  Downloading jedi-0.11.1-py2.py3-none-any.whl (250 kB)
Collecting parso==0.1.1
  Downloading parso-0.1.1-py2.py3-none-any.whl (91 kB)
INFO: pip is looking at multiple versions of parso to determine which version is compatible with other requirements. This could take a while.
Collecting jedi>=0.10
  Downloading jedi-0.11.0-py2.py3-none-any.whl (146 kB)
Collecting parso==0.1.0
  Downloading parso-0.1.0-py2.py3-none-any.whl (89 kB)
Collecting jedi>=0.10
  Downloading jedi-0.10.2-py2.py3-none-any.whl (190 kB)
  Downloading jedi-0.10.1-py2.py3-none-any.whl (179 kB)
  Downloading jedi-0.10.0-py2.py3-none-any.whl (186 kB)
INFO: pip is looking at multiple versions of ipython to determine which version is compatible with other requirements. This could take a while.
Collecting ipython
  Downloading ipython-7.18.1-py3-none-any.whl (786 kB)
  Downloading ipython-7.18.0-py3-none-any.whl (786 kB)
  Downloading ipython-7.17.0-py3-none-any.whl (786 kB)
  Downloading ipython-7.16.1-py3-none-any.whl (785 kB)
INFO: pip is looking at multiple versions of parso to determine which version is compatible with other requirements. This could take a while.
  Downloading ipython-7.16.0-py3-none-any.whl (785 kB)
  Downloading ipython-7.15.0-py3-none-any.whl (783 kB)
  Downloading ipython-7.14.0-py3-none-any.whl (782 kB)
INFO: This is taking longer than usual. You might need to provide the dependency resolver with stricter constraints to reduce runtime. If you want to abort this run, you can press Ctrl + C to do so. To improve how pip performs, tell us what happened here: https://pip.pypa.io/surveys/backtracking
INFO: pip is looking at multiple versions of ipython to determine which version is compatible with other requirements. This could take a while.
  Downloading ipython-7.13.0-py3-none-any.whl (780 kB)
  Downloading ipython-7.12.0-py3-none-any.whl (777 kB)
  Downloading ipython-7.11.1-py3-none-any.whl (777 kB)
  Downloading ipython-7.11.0-py3-none-any.whl (777 kB)
  Downloading ipython-7.10.2-py3-none-any.whl (778 kB)
INFO: This is taking longer than usual. You might need to provide the dependency resolver with stricter constraints to reduce runtime. If you want to abort this run, you can press Ctrl + C to do so. To improve how pip performs, tell us what happened here: https://pip.pypa.io/surveys/backtracking
  Downloading ipython-7.10.1-py3-none-any.whl (778 kB)
  Downloading ipython-7.10.0-py3-none-any.whl (776 kB)
  Downloading ipython-7.9.0-py3-none-any.whl (775 kB)
  Downloading ipython-7.8.0-py3-none-any.whl (775 kB)
  Downloading ipython-7.7.0-py3-none-any.whl (774 kB)
  Downloading ipython-7.6.1-py3-none-any.whl (774 kB)
  Downloading ipython-7.6.0-py3-none-any.whl (774 kB)
  Downloading ipython-7.5.0-py3-none-any.whl (770 kB)
  Downloading ipython-7.4.0-py3-none-any.whl (769 kB)
  Downloading ipython-7.3.0-py3-none-any.whl (768 kB)
  Downloading ipython-7.2.0-py3-none-any.whl (765 kB)
  Downloading ipython-7.1.1-py3-none-any.whl (764 kB)
  Downloading ipython-7.0.1-py3-none-any.whl (760 kB)
  Downloading ipython-7.0.0-py3-none-any.whl (760 kB)
  Downloading ipython-6.5.0-py3-none-any.whl (748 kB)
  Downloading ipython-6.4.0-py3-none-any.whl (750 kB)
  Downloading ipython-6.3.1-py3-none-any.whl (749 kB)
  Downloading ipython-6.3.0-py3-none-any.whl (749 kB)
  Downloading ipython-6.2.1-py3-none-any.whl (745 kB)
  Downloading ipython-6.2.0-py3-none-any.whl (745 kB)
  Downloading ipython-6.1.0-py3-none-any.whl (741 kB)
  Downloading ipython-6.0.0-py3-none-any.whl (736 kB)
  Downloading ipython-5.10.0-py3-none-any.whl (760 kB)
  Downloading ipython-5.9.0-py3-none-any.whl (760 kB)
  Downloading ipython-5.8.0-py3-none-any.whl (758 kB)
  Downloading ipython-5.7.0-py3-none-any.whl (760 kB)
  Downloading ipython-5.6.0-py3-none-any.whl (760 kB)
  Downloading ipython-5.5.0-py3-none-any.whl (758 kB)
  Downloading ipython-5.4.1-py3-none-any.whl (757 kB)
  Downloading ipython-5.4.0-py3-none-any.whl (757 kB)
  Downloading ipython-5.3.0-py3-none-any.whl (750 kB)
  Downloading ipython-5.2.2-py3-none-any.whl (749 kB)
  Downloading ipython-5.2.1-py3-none-any.whl (749 kB)
  Downloading ipython-5.2.0-py3-none-any.whl (749 kB)
  Downloading ipython-5.1.0-py3-none-any.whl (747 kB)
  Downloading ipython-5.0.0-py2.py3-none-any.whl (743 kB)
INFO: pip is looking at multiple versions of ipykernel to determine which version is compatible with other requirements. This could take a while.
Collecting ipykernel>=4.5.1
  Downloading ipykernel-5.4.1-py3-none-any.whl (119 kB)
  Downloading ipykernel-5.4.0-py3-none-any.whl (119 kB)
  Downloading ipykernel-5.3.4-py3-none-any.whl (120 kB)
  Downloading ipykernel-5.3.3-py3-none-any.whl (120 kB)
  Downloading ipykernel-5.3.2-py3-none-any.whl (120 kB)
  Downloading ipykernel-5.3.1-py3-none-any.whl (120 kB)
  Downloading ipykernel-5.3.0-py3-none-any.whl (119 kB)
INFO: pip is looking at multiple versions of ipykernel to determine which version is compatible with other requirements. This could take a while.
  Downloading ipykernel-5.2.1-py3-none-any.whl (118 kB)
  Downloading ipykernel-5.2.0-py3-none-any.whl (117 kB)
  Downloading ipykernel-5.1.4-py3-none-any.whl (116 kB)
  Downloading ipykernel-5.1.3-py3-none-any.whl (116 kB)
  Downloading ipykernel-5.1.2-py3-none-any.whl (116 kB)


Command killed due to excessive memory consumption