• I have searched the issues of this repo and believe that this is not a duplicate.
• I have searched the documentation and believe that my question is not covered.

Question

I was wondering how poetry chooses which pip version it uses when installing new packages? And how can we make it choose a different one?

I am asking this question because of the following problem I encountered:

While trying to install "cryptography" in a Docker container with poetry I got the following error message:

Command ['/root/.cache/pypoetry/virtualenvs/hybrid-py3.7/bin/pip', 'install'  
, '--no-deps', 'cryptography==2.4.2'] errored with the following output:      
Collecting cryptography==2.4.2                                                
  Downloading https://files.pythonhosted.org/packages/f3/39/d3904df7c56f8654  
691c4ae1bdb270c1c9220d6da79bd3b1fbad91afd0e1/cryptography-2.4.2.tar.gz (468k  
B)                                                                            
  Could not find a version that satisfies the requirement cffi!=1.11.3,>=1.7  
 (from versions: )                                                            
No matching distribution found for cffi!=1.11.3,>=1.7                         
You are using pip version 10.0.1, however version 18.1 is available.    

I found the error a little bit weird in the first place, because it does not occur when I run poetry install locally, but after a little bit of googling it seemed that the cffi problem was related to the pip version and should be fixable, by upgrading pip => which leads to my question: My dockerfile is based on python:3.7-alpine and has pip 18.1 installed, so why does poetry still try to use pip version 10.0.1?

Thanks a lot to anyone taking the time to read through this :)

Edit: To fix my issue, I just had to do poetry run pip install --upgrade pip before poetry install, but I guess my question where poetry gets the idea to use 10.0.1 from still holds? :)