Pip 20.2.4 goes into infinite resolution of dependencies

[romaingz]

Hello,

My CI goes into infinite resolution when trying to install a project's dependencies for testing:

pip install -e .[test] --use-feature=2020-resolver -i https://artifactory.company.com/api/pypi/pypi/simple

Output

Looking in indexes: https://artifactory.company.com/api/pypi/pypi/simple
Collecting deprecation
  Downloading https://artifactory.company.com/api/pypi/pypi/packages/packages/02/c3/253a89ee03fc9b9682f1541728eb66db7db22148cd94f89ab22528cd1e1b/deprecation-2.1.0-py2.py3-none-any.whl (11 kB)
Collecting six
  Downloading https://artifactory.company.com/api/pypi/pypi/packages/packages/ee/ff/48bde5c0f013094d729fe4b0316ba2a24774b3ff1c52d924a8a4cb04078a/six-1.15.0-py2.py3-none-any.whl (10 kB)
Collecting toolz
  Downloading https://artifactory.company.com/api/pypi/pypi/packages/packages/12/f5/537e55f8ba664ff2a26f26913010fb0fcb98b6bbadc6158af888184fd0b7/toolz-0.11.1-py3-none-any.whl (55 kB)
Collecting packaging
  Downloading https://artifactory.company.com/api/pypi/pypi/packages/packages/46/19/c5ab91b1b05cfe63cccd5cfc971db9214c6dd6ced54e33c30d5af1d2bc43/packaging-20.4-py2.py3-none-any.whl (37 kB)
Collecting pyparsing>=2.0.2
  Downloading https://artifactory.company.com/api/pypi/pypi/packages/packages/8a/bb/488841f56197b13700afd5658fc279a2025a39e22449b7cf29864669b15d/pyparsing-2.4.7-py2.py3-none-any.whl (67 kB)
Installing collected packages: six, pyparsing, packaging, toolz, deprecation
Successfully installed deprecation-2.1.0 packaging-20.4 pyparsing-2.4.7 six-1.15.0 toolz-0.11.1
�[32;1m$ pip install git+https://${CI_REGISTRY_USER}:${CI_JOB_TOKEN}@gitlab.company.com/proj/pygraph.git@Dev_Py3 ${PIP_OPTS}�[0;m
Looking in indexes: https://artifactory.company.com/api/pypi/pypi/simple
Collecting git+https://gitlab-ci-token:****@gitlab.company.com/proj/pygraph.git@Dev_Py3
  Cloning https://gitlab-ci-token:****@gitlab.company.com/proj/pygraph.git (to revision Dev_Py3) to /tmp/pip-req-build-eulnmcb2
Collecting networkx==2.*
  Downloading https://artifactory.company.com/api/pypi/pypi/packages/packages/9b/cd/dc52755d30ba41c60243235460961fc28022e5b6731f16c268667625baea/networkx-2.5-py3-none-any.whl (1.6 MB)
Collecting redis
  Downloading https://artifactory.company.com/api/pypi/pypi/packages/packages/a7/7c/24fb0511df653cf1a5d938d8f5d19802a88cef255706fdda242ff97e91b7/redis-3.5.3-py2.py3-none-any.whl (72 kB)
Collecting decorator>=4.3.0
  Downloading https://artifactory.company.com/api/pypi/pypi/packages/packages/ed/1b/72a1821152d07cf1d8b6fce298aeb06a7eb90f4d6d41acec9861e7cc6df0/decorator-4.4.2-py2.py3-none-any.whl (9.2 kB)
Building wheels for collected packages: graph-pygraph
  Building wheel for graph-pygraph (setup.py): started
  Building wheel for graph-pygraph (setup.py): finished with status 'done'
  Created wheel for graph-pygraph: filename=graph_pygraph-0.0.202010091542+devpy3-py3-none-any.whl size=71373 sha256=610fe21400ba7adec344b8345b819d42244631d11227a24bfb0fe068c959c309
  Stored in directory: /tmp/pip-ephem-wheel-cache-ovmjos36/wheels/7e/80/09/96d325dfa75fe4d16a6345d433dc8d944ebe48f4a049a12633
Successfully built graph-pygraph
Installing collected packages: decorator, redis, networkx, graph-pygraph
Successfully installed decorator-4.4.2 graph-pygraph-0.0.202010091542+devpy3 networkx-2.5 redis-3.5.3
�[32;1m$ pip install git+https://${CI_REGISTRY_USER}:${CI_JOB_TOKEN}@gitlab.company.com/proj/parser.git@Dev_Py3 ${PIP_OPTS}�[0;m
Looking in indexes: https://artifactory.company.com/api/pypi/pypi/simple
Collecting git+https://gitlab-ci-token:****@gitlab.company.com/proj/parser.git@Dev_Py3
  Cloning https://gitlab-ci-token:****@gitlab.company.com/proj/parser.git (to revision Dev_Py3) to /tmp/pip-req-build-h_satb7q
Requirement already satisfied: deprecation in ./.venv/lib/python3.6/site-packages (from graph-parser==0.0.202009100923+devpy3) (2.1.0)
Requirement already satisfied: six in ./.venv/lib/python3.6/site-packages (from graph-parser==0.0.202009100923+devpy3) (1.15.0)
Collecting defusedxml
  Downloading https://artifactory.company.com/api/pypi/pypi/packages/packages/06/74/9b387472866358ebc08732de3da6dc48e44b0aacd2ddaa5cb85ab7e986a2/defusedxml-0.6.0-py2.py3-none-any.whl (23 kB)
Requirement already satisfied: packaging in ./.venv/lib/python3.6/site-packages (from deprecation->graph-parser==0.0.202009100923+devpy3) (20.4)
Requirement already satisfied: six in ./.venv/lib/python3.6/site-packages (from graph-parser==0.0.202009100923+devpy3) (1.15.0)
Requirement already satisfied: pyparsing>=2.0.2 in ./.venv/lib/python3.6/site-packages (from packaging->deprecation->graph-parser==0.0.202009100923+devpy3) (2.4.7)
Building wheels for collected packages: graph-parser
  Building wheel for graph-parser (setup.py): started
  Building wheel for graph-parser (setup.py): finished with status 'done'
  Created wheel for graph-parser: filename=graph_parser-0.0.202009100923+devpy3-py3-none-any.whl size=20698 sha256=f2d7b651180d9f844b7aafe8b9431938ceecbfec798407c47b7258b94528c75c
  Stored in directory: /tmp/pip-ephem-wheel-cache-bmna_g2x/wheels/fb/eb/f2/38806b77dcb72c250f63911a3567922b604ab6e88ab74ff980
Successfully built graph-parser
Installing collected packages: defusedxml, graph-parser
Successfully installed defusedxml-0.6.0 graph-parser-0.0.202009100923+devpy3
�[32;1m$ pip install git+https://${CI_REGISTRY_USER}:${CI_JOB_TOKEN}@gitlab.company.com/proj/interfaces.git@Dev_Py3 --no-deps ${PIP_OPTS}�[0;m
Looking in indexes: https://artifactory.company.com/api/pypi/pypi/simple
Collecting git+https://gitlab-ci-token:****@gitlab.company.com/proj/interfaces.git@Dev_Py3
  Cloning https://gitlab-ci-token:****@gitlab.company.com/proj/interfaces.git (to revision Dev_Py3) to /tmp/pip-req-build-20dgw2sv
Building wheels for collected packages: graph-interfaces
  Building wheel for graph-interfaces (setup.py): started
  Building wheel for graph-interfaces (setup.py): finished with status 'done'
  Created wheel for graph-interfaces: filename=graph_interfaces-0.0.202009180922+devpy3-py3-none-any.whl size=36309 sha256=4a461620d4810f49bd1072a202ab767d56a171bcaa6c5609dcdbaadcc7c4f0a9
  Stored in directory: /tmp/pip-ephem-wheel-cache-5fdbdk3o/wheels/03/ab/79/5bc1653cb185c54b17d12b2b8d495e5231cf117605d3073d9e
Successfully built graph-interfaces
Installing collected packages: graph-interfaces
Successfully installed graph-interfaces-0.0.202009180922+devpy3
�[32;1m$ pip install git+https://${CI_REGISTRY_USER}:${CI_JOB_TOKEN}@gitlab.company.com/proj/post-binding.git@Dev_Py3 --no-deps ${PIP_OPTS}�[0;m
Looking in indexes: https://artifactory.company.com/api/pypi/pypi/simple
Collecting git+https://gitlab-ci-token:****@gitlab.company.com/proj/post-binding.git@Dev_Py3
  Cloning https://gitlab-ci-token:****@gitlab.company.com/proj/post-binding.git (to revision Dev_Py3) to /tmp/pip-req-build-94mbisdx
Building wheels for collected packages: graph-post-bindings
  Building wheel for graph-post-bindings (setup.py): started
  Building wheel for graph-post-bindings (setup.py): finished with status 'done'
  Created wheel for graph-post-bindings: filename=graph_post_bindings-Dev-py3-none-any.whl size=211749 sha256=efbf8dfa72e4e461740a19a1208952d712fdcace52f17379fd7ad18d9da3b912
  Stored in directory: /tmp/pip-ephem-wheel-cache-vwr6n_g0/wheels/43/7e/ef/8849b821244fee59fc5b97c8694cf87e5609633ea26d65f8a0
Successfully built graph-post-bindings
Installing collected packages: graph-post-bindings
Successfully installed graph-post-bindings-Dev
�[32;1m$ pip install -e .[test] ${PIP_OPTS}�[0;m
Looking in indexes: https://artifactory.company.com/api/pypi/pypi/simple
Obtaining file:///tmp/proj/scenarios
Requirement already satisfied: graph-pygraph<1 in ./.venv/lib/python3.6/site-packages (from graph-scenarios==0.0.202010191027+unknown) (0.0.202010091542+devpy3)
Requirement already satisfied: graph-interfaces<1 in ./.venv/lib/python3.6/site-packages (from graph-scenarios==0.0.202010191027+unknown) (0.0.202009180922+devpy3)
Requirement already satisfied: graph-parser<1 in ./.venv/lib/python3.6/site-packages (from graph-scenarios==0.0.202010191027+unknown) (0.0.202009100923+devpy3)
Requirement already satisfied: graph-post_bindings==Dev in ./.venv/lib/python3.6/site-packages (from graph-scenarios==0.0.202010191027+unknown) (Dev)
Requirement already satisfied: toolz in ./.venv/lib/python3.6/site-packages (from graph-scenarios==0.0.202010191027+unknown) (0.11.1)
Requirement already satisfied: graph-pygraph<1 in ./.venv/lib/python3.6/site-packages (from graph-scenarios==0.0.202010191027+unknown) (0.0.202010091542+devpy3)
Requirement already satisfied: graph-interfaces<1 in ./.venv/lib/python3.6/site-packages (from graph-scenarios==0.0.202010191027+unknown) (0.0.202009180922+devpy3)
Requirement already satisfied: graph-parser<1 in ./.venv/lib/python3.6/site-packages (from graph-scenarios==0.0.202010191027+unknown) (0.0.202009100923+devpy3)
Requirement already satisfied: graph-post_bindings==Dev in ./.venv/lib/python3.6/site-packages (from graph-scenarios==0.0.202010191027+unknown) (Dev)
Requirement already satisfied: toolz in ./.venv/lib/python3.6/site-packages (from graph-scenarios==0.0.202010191027+unknown) (0.11.1)
Collecting cerberus
  Downloading https://artifactory.company.com/api/pypi/pypi/packages/packages/90/a7/71c6ed2d46a81065e68c007ac63378b96fa54c7bb614d653c68232f9c50c/Cerberus-1.3.2.tar.gz (52 kB)
Requirement already satisfied: setuptools in ./.venv/lib/python3.6/site-packages (from cerberus->graph-scenarios==0.0.202010191027+unknown) (50.3.2)
Requirement already satisfied: redis in ./.venv/lib/python3.6/site-packages (from graph-pygraph<1->graph-scenarios==0.0.202010191027+unknown) (3.5.3)
Requirement already satisfied: networkx==2.* in ./.venv/lib/python3.6/site-packages (from graph-pygraph<1->graph-scenarios==0.0.202010191027+unknown) (2.5)
Requirement already satisfied: graph-parser<1 in ./.venv/lib/python3.6/site-packages (from graph-scenarios==0.0.202010191027+unknown) (0.0.202009100923+devpy3)
Requirement already satisfied: graph-pygraph<1 in ./.venv/lib/python3.6/site-packages (from graph-scenarios==0.0.202010191027+unknown) (0.0.202010091542+devpy3)
Requirement already satisfied: redis in ./.venv/lib/python3.6/site-packages (from graph-pygraph<1->graph-scenarios==0.0.202010191027+unknown) (3.5.3)
Requirement already satisfied: deprecation in ./.venv/lib/python3.6/site-packages (from graph-parser<1->graph-scenarios==0.0.202010191027+unknown) (2.1.0)
Requirement already satisfied: six in ./.venv/lib/python3.6/site-packages (from graph-parser<1->graph-scenarios==0.0.202010191027+unknown) (1.15.0)
Requirement already satisfied: defusedxml in ./.venv/lib/python3.6/site-packages (from graph-parser<1->graph-scenarios==0.0.202010191027+unknown) (0.6.0)
Requirement already satisfied: toolz in ./.venv/lib/python3.6/site-packages (from graph-scenarios==0.0.202010191027+unknown) (0.11.1)
Collecting graph-parser<1
  Downloading https://artifactory.company.com/api/pypi/pypi/graph-parser/0.0.202009100923%2Bunknown/graph_parser-0.0.202009100923%2Bunknown-py3-none-any.whl (20 kB)
Requirement already satisfied: deprecation in ./.venv/lib/python3.6/site-packages (from graph-parser<1->graph-scenarios==0.0.202010191027+unknown) (2.1.0)
Requirement already satisfied: six in ./.venv/lib/python3.6/site-packages (from graph-parser<1->graph-scenarios==0.0.202010191027+unknown) (1.15.0)
Requirement already satisfied: defusedxml in ./.venv/lib/python3.6/site-packages (from graph-parser<1->graph-scenarios==0.0.202010191027+unknown) (0.6.0)
Requirement already satisfied: toolz in ./.venv/lib/python3.6/site-packages (from graph-scenarios==0.0.202010191027+unknown) (0.11.1)

I get the last 4 lines repeating forever:

Requirement already satisfied: deprecation in ./.venv/lib/python3.6/site-packages (from graph-parser<1->graph-scenarios==0.0.202010191027+unknown) (2.1.0)
Requirement already satisfied: six in ./.venv/lib/python3.6/site-packages (from graph-parser<1->graph-scenarios==0.0.202010191027+unknown) (1.15.0)
Requirement already satisfied: defusedxml in ./.venv/lib/python3.6/site-packages (from graph-parser<1->graph-scenarios==0.0.202010191027+unknown) (0.6.0)
Requirement already satisfied: toolz in ./.venv/lib/python3.6/site-packages (from graph-scenarios==0.0.202010191027+unknown) (0.11.1)

Additional information

In the above output, PIP_OPTS is set to --use-feature=2020-resolver -i https://artifactory.company.com/api/pypi/pypi/simple.

We use a company hosted index that does not have any issues with pip==20.2.3.

[pradyunsg]

Hi! Thanks for filing this issue! Could you share the requirements that pip is trying to install? This would be in the setup.py/pyproject.toml for the relevant project.

[romaingz]

The "public" dependencies are:

    install_requires=[
        'cerberus',
        '<inhouse component 1>',
        '<inhouse component 2>',
        '<inhouse component 3>',
        '<inhouse component 4>',
        '<inhouse component 5>',
        'pint',
        '<inhouse component 6>',
        '<inhouse component 7>',
        'toolz',
        'pyyaml>=5.1',
    ],
    extras_require={'test': ['pylint', 'pytest>=4', 'pytest-cov', 'pytest-html', 'pytest-xdist',]},

however as you can see we have multiple inhouse libraries that are also required.

Here's a pip list of what version 20.2.3 installs in case it helps:

$ pip list
Package              Version                  Location
-------------------- ------------------------ ------------------
amqp                 5.0.1
apipkg               1.5
asteval              0.9.19
astroid              2.4.2
attrs                20.2.0
<inhouse>
billiard             3.6.3.0
celery               5.0.1
Cerberus             1.3.2
certifi              2020.6.20
chardet              3.0.4
click                7.1.2
click-didyoumean     0.0.3
click-repl           0.1.6
coverage             5.3
cycler               0.10.0
decorator            4.4.2
defusedxml           0.6.0
deprecation          2.1.0
execnet              1.7.1
future               0.18.2
<inhouse>
<inhouse>
<inhouse>
<inhouse>
<inhouse>
h5py                 2.10.0
importlib-metadata   2.0.0
importlib-resources  3.0.0
iniconfig            1.1.1
isort                5.6.4
kiwisolver           1.2.0
kombu                5.0.2
lazy-object-proxy    1.4.3
<inhouse>
lmfit                1.0.1
matplotlib           3.3.2
mccabe               0.6.1
munch                2.5.0
networkx             2.5
numpy                1.19.2
packaging            20.4
pandas               1.1.3
Pillow               8.0.0
Pint                 0.16.1
pip                  20.2.3
pluggy               0.13.1
<inhouse>
<inhouse>
prompt-toolkit       3.0.8
py                   1.9.0
<inhouse>
<inhouse>
<inhouse>
pylint               2.6.0
pyparsing            2.4.7
<inhouse>
pytest               6.1.1
pytest-cov           2.10.1
pytest-forked        1.3.0
pytest-html          2.1.1
pytest-metadata      1.10.0
WARNING: You are using pip version 20.2.3; however, version 20.2.4 is available.
You should consider upgrading via the '/tmp/ues/scenarios/.venv/bin/python -m pip install --upgrade pip' command.
pytest-xdist         2.1.0
python-dateutil      2.8.1
pytz                 2020.1
PyYAML               5.3.1
redis                3.5.3
scipy                1.5.3
setuptools           50.3.2
six                  1.15.0
tabulate             0.8.7
toml                 0.10.1
toolz                0.11.1
typed-ast            1.4.1
uncertainties        3.1.4
vine                 5.0.0
wcwidth              0.2.5
wheel                0.35.1
wrapt                1.12.1
xlwt                 1.3.0
zipp                 3.3.1

[romaingz]

Not sure if it will end up being relevant, but it might be worth noting that I pre-pip install deprecation six toolz, meaning that I actually do:

pip install deprecation six toolz ${PIP_OPTS}
# some more pip installation using the new resolver
pip install -e .[test] ${PIP_OPTS}

[pradyunsg]

Thanks for sharing that. However, this information still isn't sufficient to reproduce this issue. :(

I'd basically need the entire mapping of (package-name, version): [dependencies] that pip sees during the resolution process to be able to debug this, and I obviously can't look up the dependencies of your internal packages. ;)

So, a couple of related questions:

• could you possibly create a minimal reproducer for this, so that we can try this without needing access to the internal packages? :)
  • if not, would it be possible to provide something like the mapping I mentioned above, for the packages that pip looks at during the resolution process?
• does this error occur even when installing as . instead of .[test] (i.e. without the test extra)?

I'd basically need to recreate/see what the internal state of the resolver is, when it gets stuck, which we don't print out/log anywhere for a bunch of reasons.

[romaingz]

Okay so I've been trying to reproduce the issue locally without any success.

I've tried to reproduce this in our CI on another branch and again it did not fail.

So I went back to the original branch that was have issues earlier today and switched back to 20.2.4 and it succeeded in resolving the dependencies this time...

Could this be an issue with caching or something?

Our CI works with k8s runners so I doubt this could be the case.

Should I close this and reopen if it happens again?

[pradyunsg]

Could this be an issue with caching or something?

pip doesn't cache anything during dependency resolution -- only network I/O. I don't think it could be that.

Should I close this and reopen if it happens again?

Sure! That works for me. If you are able to come up with a reproducer, that'd be awesome!

[DanSimon]

Hey, I'm also seeing a similar problem that suddenly began a day ago.

On pip 20.2.4, I'm able to reproduce this with just

pip install --use-feature=2020-resolver "google-api-core>1.18.0,<1.21.0" "google-cloud-monitoring>=2.0.0"

The behavior seems a bit non-deterministic, but each time it will start downloading many versions (possibly every version!) of a dependency and either get stuck in a Requirement already satisfied loop or just appears to freeze entirely. This is a boiled down example, but we had a CI build get stuck for 6 hours before getting killed.

Notice that the two libs I'm trying to install actually cause a version conflict and if I drop the --use-feature=2020-resolver I get a normal error message:

google-cloud-monitoring 2.0.0 requires google-api-core[grpc]<2.0.0dev,>=1.22.2, but you'll have google-api-core 1.20.1 which is incompatible.

also if I drop down to pip 20.2.3 (and use the 2020-resolver) I also quickly get a dependency conflict error.

If I change the above requirement to google-cloud-monitoring<2.0.0 then it works fine, both with and without the 2020-resolver

Hope this helps

[simonw]

I just ran into this as well - I ran the new resolver against an existing (quite large) requirements.txt file and it ended up running into an infinite loop of Requirement already satisfied.

Here are my steps to reproduce: https://gist.github.com/simonw/c53ad97ac2cd495e741b52f88d22b45d

Shorter version: I ran pip install --use-feature=2020-resolver -r requirements.txt against this file: https://gist.githubusercontent.com/simonw/c53ad97ac2cd495e741b52f88d22b45d/raw/e09640304fcdf1990844f8ff8ecc92ef654d21b7/requirements.txt

[simonw]

Running without the --use-feature= flag gives me this:

ERROR: After October 2020 you may experience errors when installing or updating packages. This is because pip will change the way that it resolves dependency conflicts.

We recommend you use --use-feature=2020-resolver to test your packages with the new resolver before it becomes the default.

pocket-to-sqlite 0.2 requires sqlite-utils~=2.4.4, but you'll have sqlite-utils 2.22 which is incompatible.
healthkit-to-sqlite 0.5 requires sqlite-utils~=2.4.4, but you'll have sqlite-utils 2.22 which is incompatible.

Though oddly the infinite loop problem didn't mention those packages - it looked like this:

Collecting twitter-to-sqlite~=0.20
  Using cached twitter_to_sqlite-0.20-py3-none-any.whl (25 kB)
Requirement already satisfied: click~=7.1.1 in /Users/simon/.local/share/virtualenvs/pipnext-HNJm0oR8/lib/python3.8/site-packages (from datasette>=0.50.2->-r requirements.txt (line 2)) (7.1.2)
Requirement already satisfied: click~=7.1.1 in /Users/simon/.local/share/virtualenvs/pipnext-HNJm0oR8/lib/python3.8/site-packages (from datasette>=0.50.2->-r requirements.txt (line 2)) (7.1.2)
...