[1.1.0b2] Bumping version leaves orphaned dist-info in site-packages

• I am on the latest Poetry version.

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

• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option).

• OS version and name: elementary OS 5.1 Hera

• Poetry version: 1.1.0b2

• Link of a Gist with the contents of your pyproject.toml file: https://gist.github.com/MrGreenTea/992a1795471c00d727c02920d4288f16

Issue

When updating my packages version with poetry version old dist-info directories are left in site-packages. This trips up pip, importlib and pkg_resources for example when trying to find the packages information. To reproduce: (run with poetry config virtualenvs.in-project true)

1. ❯ poetry new example
2. ❯ poetry install
3. ❯ ls .venv/lib/python3.8/site-packages/example*.dist-info

.venv/lib/python3.8/site-packages/example-0.1.0.dist-info:
INSTALLER  METADATA  RECORD

1. ❯ poetry version minor && poetry install
2. ❯ ls .venv/lib/python3.8/site-packages/example*.dist-info

.venv/lib/python3.8/site-packages/example-0.1.0.dist-info:
INSTALLER  METADATA  RECORD

.venv/lib/python3.8/site-packages/example-0.2.0.dist-info:
INSTALLER  METADATA  RECORD

1. ❯ poetry run pip show example

Name: example
Version: 0.2.0
Summary: 
Home-page: None
Author: Jonas Bulik
Author-email: [e-mail]
License: None
Location: /tmp/example/.venv/lib/python3.8/site-packages
Requires: 
Required-by: 

1. ❯ poetry version 0.1.0
2. ❯ poetry run pip show example

Name: example
Version: 0.2.0
Summary: 
Home-page: None
Author: Jonas Bulik
Author-email: [e-mail]
License: None
Location: /tmp/example/.venv/lib/python3.8/site-packages
Requires: 
Required-by: 

[abn]

Oh, I misread the issue. Looks like there is a new issue in the lines not being updated during install. But this might not be related to the #3900 fix.

Also you will note that in 1.1.5 you will have seen;

The virtual environment found in /home/fredrik/code/repos/a/.venv seems to be broken.

This is because the new venv does not have pip in it (#2826).

[abn]

That is expected. Because of #3876. There are followup fixes for that in #3891 and #3900.