I'm trying to move away from *.in files and manage everything from pyproject.toml, but I'm facing a problem where pip-compile --extra doesn't take into account the already pinned versions from pip-compile (without --extra).

Environment Versions

1. OS Type: Arch Linux
2. Python version: 3.11.3
3. pip version: pip 23.1.2 from /usr/lib/python3.11/site-packages/pip (python 3.11)
4. pip-tools version: 6.13.0

Steps to replicate

1. Create the following pyproject.toml:

[build-system]
requires = ["hatchling"]
build-backend = "hatchling.build"

[project]
name = "foobar"
version = "1"
dependencies = ["django==4.1.7"]

[project.optional-dependencies]
dev = ["pytest"]

3. Execute pip-compile --no-header --no-annotate --resolver backtracking to obtain:

asgiref==3.7.2
django==4.1.7
sqlparse==0.4.4

5. Remove the restriction from the django dependency from the pyproject.toml, and verify that pip-compile doesn't update any package.
6. Execute pip-compile --no-header --no-annotate --resolver backtracking --extra dev -o dev-requirements.txt, and see that the django dependency has been updated in the dev-requirements.txt:

asgiref==3.7.2
django==4.2.2
iniconfig==2.0.0
packaging==23.1
pluggy==1.2.0
pytest==7.4.0
sqlparse==0.4.4

I also tried to pass --pip-args "-c requirements.txt", but nothing changed.

Expected result

Actually, I would expect a way to pin only the dev dependencies, since the main dependencies were already pinned. Some workflow similar to the Workflow for layered requirements but with pyproject.toml instead of *.in files.