pip-compile includes irrelevant constraints from pip contraints file

[derek-miller]

pip-compile treats constraints as requirements.

https://pip.pypa.io/en/stable/user_guide/#constraints-files

Steps to replicate

1. Create a constraints.txt file with the following contents:

click==6  # Irrelevant package
itsdangerous==0.24

2. Create a requirements.in file with the following contents:

-c constraints.txt
Flask

2. run pip-compile

Expected result

#
# This file is autogenerated by pip-compile
# To update, run:
#
#    pip-compile --output-file requirements.txt requirements.in
#

Flask==0.11.1
itsdangerous==0.24
Jinja2==2.8               # via flask
MarkupSafe==0.23          # via jinja2
Werkzeug==0.11.11         # via flask

Actual result

#
# This file is autogenerated by pip-compile
# To update, run:
#
#    pip-compile --output-file requirements.txt requirements.in
#

click==6.0
Flask==0.11.1
itsdangerous==0.24
Jinja2==2.8               # via flask
MarkupSafe==0.23          # via jinja2
Werkzeug==0.11.11         # via flask

[derek-miller]

Anyone have time to review this?

[davidovich]

Thanks @derek-miller !

[davidovich]

I have no problem with the fix, it's just that it works very well without the memoization... Would you mind taking #485 for a spin and see if your use case is broken ?