pip 20.3 use new dependency resolver that breaks current config

.gitlab-ci.yml

@@ -11,8 +11,8 @@ variables:
   stage: test
   before_script:
     - apt-get update && apt-get install -y --allow-unauthenticated libsasl2-dev libssl-dev locales locales-all
-    - pip install -r requirements.txt --default-timeout=180 -i https://pypi.lcsb.uni.lu/simple/
-    - pip install -r requirements-dev.txt --default-timeout=180 -i https://pypi.lcsb.uni.lu/simple/
+    - pip install --use-deprecated=legacy-resolver -r requirements.txt --default-timeout=180 -i https://pypi.lcsb.uni.lu/simple/
+    - pip install --use-deprecated=legacy-resolver -r requirements-dev.txt --default-timeout=180 -i https://pypi.lcsb.uni.lu/simple/
 
 test_postgres:
     <<: *test_definition

Dockerfile

@@ -4,7 +4,7 @@ RUN mkdir /code
 WORKDIR /code
 RUN apt-get update && apt-get install -y --allow-unauthenticated libsasl2-dev libssl-dev locales locales-all 
 ADD requirements* /code/
-RUN pip install -r requirements.txt --default-timeout=180 -i https://pypi.lcsb.uni.lu/simple/ && pip install -r requirements-dev.txt --default-timeout=180 -i https://pypi.lcsb.uni.lu/simple/ # --use-feature=2020-resolver
+RUN pip install --use-deprecated=legacy-resolver -r requirements.txt --default-timeout=180 -i https://pypi.lcsb.uni.lu/simple/ && pip install --use-deprecated=legacy-resolver -r requirements-dev.txt --default-timeout=180 -i https://pypi.lcsb.uni.lu/simple/ # --use-feature=2020-resolver
 ADD . /code/
 RUN cp local_settings_ci.py smash/smash/local_settings.py
 WORKDIR /code/smash

debian-template/postinst

@@ -26,8 +26,8 @@ fi
 
 echo "Installing python dependencies"
 {
-  source /usr/lib/smasch/env/bin/activate && pip install -r /usr/lib/smasch/requirements.txt --log $LOG_FILE
-  source /usr/lib/smasch/env/bin/activate && pip install -r /usr/lib/smasch/requirements-dev.txt  --log $LOG_FILE
+  source /usr/lib/smasch/env/bin/activate && pip install -r --use-deprecated=legacy-resolver /usr/lib/smasch/requirements.txt --log $LOG_FILE
+  source /usr/lib/smasch/env/bin/activate && pip install -r --use-deprecated=legacy-resolver /usr/lib/smasch/requirements-dev.txt  --log $LOG_FILE
 } || {
   echo "There was an issue when installing python dependencies." >> $LOG_FILE
   echo "There was an issue when installing python dependencies. Reinstall of smasch could help (in case you are upgrading smasch the data should not be lost in the process): "

readme.md

@@ -26,7 +26,7 @@ python manage.py createsuperuser
   - `cd scheduling-system`
   - `virtualenv env` to create new virtualenv (contains clean python working environment)
   - `. env/bin/activate` (to start using virtualenv)
-  - `pip install -r requirements.txt` to install project's dependencies
+  - `pip install --use-deprecated=legacy-resolver -r requirements.txt` to install project's dependencies
   - Create `local_settings.py` file in `(./scheduling-system)/smash/smash` directory by copying the template in `(./scheduling-system)/smash/smash/local_settings.template` and edit your local_setttings.py file to change your database connection data.
 
  - Update migration db scrpit from file structure (`./scheduling-system/smash/manage.py makemigrations`)