bug: failed to resolve dependency with `platform_system`

[BeautyyuYanli]

• [x] I have searched the issue tracker and believe that this is not a duplicate.

Steps to reproduce

I'm tring to install trafilatura>=1.6.2 and it reports:

Unable to find a resolution for lxml
because of the following conflicts:
  lxml==4.9.2; platform_system == "Darwin" (from trafilatura@1.6.2)
  lxml>=4.9.3; platform_system != "Darwin" (from trafilatura@1.6.2)
To fix this, you could loosen the dependency version constraints in pyproject.toml. See 
https://pdm-project.org/latest/usage/dependency/#solve-the-locking-failure for more details.

Actual behavior

Expected behavior

Environment Information

PDM version:
  2.10.1
Python Interpreter:
  /home/beautyyu/Development/gugu-helper/.venv/bin/python (3.11)
Project Root:
  /home/beautyyu/Development/gugu-helper
Local Packages:

{
  "implementation_name": "cpython",
  "implementation_version": "3.11.3",
  "os_name": "posix",
  "platform_machine": "x86_64",
  "platform_release": "6.5.9-arch2-1",
  "platform_system": "Linux",
  "platform_version": "#1 SMP PREEMPT_DYNAMIC Thu, 26 Oct 2023 00:52:20 +0000",
  "python_full_version": "3.11.3",
  "platform_python_implementation": "CPython",
  "python_version": "3.11",
  "sys_platform": "linux"
}

[pawamoy]

Workaround:

• add the dependency to pyproject manually: "trafilatura>=1.6.2"
• create a non cross-platform lock file: pdm lock -S no_cross_platform
• next executions of pdm add or pdm lock will be non cross-platform too

[frostming]

We are not able to handle this kind of dependencies for now. Refer to #46 , closing this now.