Explain resolver changes affecting constraints files

Related to #8792, #8076, #9020.
This commit is contained in:
Sumana Harihareswara 2020-10-26 21:01:18 -04:00
parent 5393032025
commit 27b100e8d1
1 changed files with 13 additions and 4 deletions

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@ -291,7 +291,10 @@ organisation and use that everywhere. If the thing being installed requires
"helloworld" to be installed, your fixed version specified in your constraints
file will be used.
Constraints file support was added in pip 7.1.
Constraints file support was added in pip 7.1. In :ref:`Resolver
changes 2020` we did a fairly comprehensive overhaul and stripped
constraints files down to being purely a way to specify global
(version) limits for packages.
.. _`Installing from Wheels`:
@ -1446,15 +1449,21 @@ install x y`` in a single command. We would like your thoughts on what
pip's behavior should be; please answer `our survey on upgrades that
create conflicts`_.
We are also changing our support for :ref:`Constraints Files` and related functionality:
We are also changing our support for :ref:`Constraints Files` and
related functionality. We did a fairly comprehensive overhaul and
stripped constraints files down to being purely a way to specify
global (version) limits for packages. Specifically:
* Constraints don't override the existing requirements; they simply
constrain what versions are visible as input to the resolver (see
:issue:`9020`)
* Providing an editable requirement (``-e .``) does not cause pip to
ignore version specifiers or constraints (see :issue:`8076`)
* Hash-checking mode requires that all requirements are specified as a
`==` match on a version and may not work well in combination with
constraints (see :issue:`9020`)
`==` match on a version and may not work well in combination with
constraints (see :issue:`9020` and :issue:`8792`)
* Unnamed requirements are not allowed as constraints (see :issue:`6628` and :issue:`8210`)
* Links are not allowed as constraints (see :issue:`8253`)