I currently have a setup.cfg with numpy==1.19.5 as dependency. When I rebuild a requirements.txt using pip-compile on Windows 10, it adds a line numpy==1.19.5+mkl which later on can't be found by my Linux Jenkins instance. How can I tell pip-compile to stop adding +mkl as a suffix to the version?

Thanks
Ingo

Environment Versions

1. Windows 10 (when run pip-compile) but Linux (when run pip-sync)
2. Python version: Python 3.6
3. pip version: 21.2.2
4. pip-tools version: 6.2.0

Steps to replicate

1. Have a setup.cfg with a

[options]
install_requires =
    numpy==1.19.5

2. run pip-compile
3. Have a look at your requirements.txt for a line numpy==1.19.5+mkl `

Expected result

It should be numpy==1.19.5

Actual result

numpy==1.19.5+mkl