Day going normally while working on converting our Python projects to use uv (Just awesome!) instead of the usual pip and while converting one of the Azure Functions Python project, I encountered the following weird error while running uv sync -

PS D:\dev\RE> uv sync
  × Failed to build `fusepy==3.0.1`
  ├─▶ The build backend returned an error
  ╰─▶ Call to `setuptools.build_meta:__legacy__.build_wheel` failed (exit code: 101)

      [stderr]
      Unable to create process using '"D:\Python-3.10.15\PCbuild\amd64\python.exe" -c "import sys

      if sys.path[0] == \"\":
          sys.path.pop(0)

      sys.path = [] + sys.path

      from setuptools.build_meta import __legacy__ as backend

      import json

      get_requires_for_build = getattr(backend, \"get_requires_for_build_wheel\", None)
      if get_requires_for_build:
          requires = get_requires_for_build({})
      else:
          requires = []

      with
      open(\"C:\\Users\\PJ\\AppData\\Local\\uv\\cache\\builds-v0\\.tmp0KnOHv\\get_requires_for_build_wheel.txt\",
      \"w\") as fp:
          json.dump(requires, fp)
      "'

      hint: This usually indicates a problem with the package or the build environment.
  help: `fusepy` (v3.0.1) was included because `RE` (v2.2.0) depends on
        `REOE==2.2.0a3` (v2.2.0a3) which depends on `azureml-sdk==1.58.0`        
        (v1.58.0) which depends on `azureml-dataset-runtime[fuse]>=1.58.0, <1.59.dev0` (v1.58.0) which       
        depends on `fusepy>=3.0.1, <4.0.0`

This was strange because this same command (uv sync) was working fine in another project I just converted. I just ran python --version on PowerShell and was greeted with the following -

PS D:\dev\RE> python --version
ResourceUnavailable: Program 'python.exe' failed to run: An error occurred trying to start process 'D:\Python-3.10.15\PCbuild\amd64\python.exe' with working directory 'D:\dev\RE'. This program is blocked by group policy. For more information, contact your system administrator.At line:1 char:1
+ python --version
+ ~~~~~~~~~~~~~~~~.

Aah! Turns out, our organization recently rolled out policies geared towards security and disabled a lot of the programs. What they have done is that in order to run anything like python, I need to escalate myself with Administrator privileges by entering the security details and then also provide justification before I could do anything.

I did the same and then ran python --version followed by uv sync which worked without any issues. The above issue happened because there were some dependencies which had to be built from source and that required Python to work.