Expected behaviour

opencv-python builds on MacOS

Actual behaviour

Receive an error stating:

ERROR: Cannot install numpy==1.21.2 and numpy==1.21.4 because these package versions have conflicting dependencies.

  The conflict is caused by:
      The user requested numpy==1.21.2
      The user requested numpy==1.21.4

• operating system == 12.6
• architecture (e.g. x86) == x86
• opencv-python version == 4.7.0.68 (commit 339bca5 on 4.x branch)

Issue submission checklist

• This is not a generic OpenCV usage question (looking for help for coding, other usage questions, homework etc.)
• I have read the README of this repository and understand that this repository provides only an automated build toolchain for OpenCV Python packages (there is no actual OpenCV code here)
• The issue is related to the build scripts in this repository, to the pre-built binaries or is a feature request (such as "please enable this additional dependency")
• I'm using the latest version of opencv-python

Fix

To me, this looks like an issue in the pyroject.toml requires array, with conflicting versions if your are running python >= 3.10 on Mac.

Specifically these lines:

  "numpy==1.21.2; python_version>='3.10'",
  "numpy==1.21.4; python_version>='3.10' and platform_system=='Darwin'",

should probably be:

  "numpy==1.21.2; python_version>='3.10' and platform_system!='Darwin'",
  "numpy==1.21.4; python_version>='3.10' and platform_system=='Darwin'",

Otherwise when python >= 3.10 and platform_system == "Darwin" it will want both numpy 1.21.2 (to satisfy the first condition) and numpy 1.21.4 (to satisfy the second).