New resolver takes a very long time to complete #9187
Description
What did you want to do?
One of CI jobs for Weblate is to install minimal versions of dependencies. We use requirements-builder to generate the minimal version requirements from the ranges we use normally.
The pip install -r requirements-min.txt command seems to loop infinitely after some time. This started to happen with 20.3, before it worked just fine.
Output
Requirement already satisfied: google-auth<2.0dev,>=1.21.1 in /opt/hostedtoolcache/Python/3.7.9/x64/lib/python3.7/site-packages (from google-api-core[grpc]<2.0.0dev,>=1.22.0->google-cloud-translate==3.0.0->-r requirements-min.txt (line 63)) (1.23.0)
Requirement already satisfied: pytz>dev in /opt/hostedtoolcache/Python/3.7.9/x64/lib/python3.7/site-packages (from celery[redis]==4.4.5->-r requirements-min.txt (line 3)) (2020.4)
Requirement already satisfied: googleapis-common-protos<2.0dev,>=1.6.0 in /opt/hostedtoolcache/Python/3.7.9/x64/lib/python3.7/site-packages (from google-api-core[grpc]<2.0.0dev,>=1.22.0->google-cloud-translate==3.0.0->-r requirements-min.txt (line 63)) (1.52.0)
Requirement already satisfied: six>=1.9.0 in /opt/hostedtoolcache/Python/3.7.9/x64/lib/python3.7/site-packages (from bleach==3.1.1->-r requirements-min.txt (line 1)) (1.15.0)
Requirement already satisfied: protobuf>=3.12.0 in /opt/hostedtoolcache/Python/3.7.9/x64/lib/python3.7/site-packages (from google-api-core[grpc]<2.0.0dev,>=1.22.0->google-cloud-translate==3.0.0->-r requirements-min.txt (line 63)) (3.14.0)
Requirement already satisfied: grpcio<2.0dev,>=1.29.0 in /opt/hostedtoolcache/Python/3.7.9/x64/lib/python3.7/site-packages (from google-api-core[grpc]<2.0.0dev,>=1.22.0->google-cloud-translate==3.0.0->-r requirements-min.txt (line 63)) (1.33.2)
Requirement already satisfied: google-auth<2.0dev,>=1.21.1 in /opt/hostedtoolcache/Python/3.7.9/x64/lib/python3.7/site-packages (from google-api-core[grpc]<2.0.0dev,>=1.22.0->google-cloud-translate==3.0.0->-r requirements-min.txt (line 63)) (1.23.0)
Requirement already satisfied: pytz>dev in /opt/hostedtoolcache/Python/3.7.9/x64/lib/python3.7/site-packages (from celery[redis]==4.4.5->-r requirements-min.txt (line 3)) (2020.4)
Requirement already satisfied: googleapis-common-protos<2.0dev,>=1.6.0 in /opt/hostedtoolcache/Python/3.7.9/x64/lib/python3.7/site-packages (from google-api-core[grpc]<2.0.0dev,>=1.22.0->google-cloud-translate==3.0.0->-r requirements-min.txt (line 63)) (1.52.0)
Requirement already satisfied: six>=1.9.0 in /opt/hostedtoolcache/Python/3.7.9/x64/lib/python3.7/site-packages (from bleach==3.1.1->-r requirements-min.txt (line 1)) (1.15.0)
Requirement already satisfied: protobuf>=3.12.0 in /opt/hostedtoolcache/Python/3.7.9/x64/lib/python3.7/site-packages (from google-api-core[grpc]<2.0.0dev,>=1.22.0->google-cloud-translate==3.0.0->-r requirements-min.txt (line 63)) (3.14.0)
This seems to repeat forever (well for 3 hours so far, see https://github.com/WeblateOrg/weblate/runs/1474960864?check_suite_focus=true)
Additional information
Requirements file triggering this: requirements-min.txt
It takes quite some time until it gets to above loop. There is most likely something problematic in the dependencies set...