Fix PermissionError when detecting package manager on WSL

[kashifkhan]

I was running into a issue when the python emitter would raise an error that uv was running in to a PermissionError. I didnt have uv installed and wanted it to use my system python instead.

This was preventing the fallback to using pip instead. In the repro below you can see python is walking down every directory in $PATH tryig to find uv. It found a stub on Windows side but then doesnt have permissions to run it.

The fix is to except on PermissionError when trying to detect the package manager so the script does the right fallback.

Error message

azure_ai_ml_tsp2) kashifkhan@CPC-kashi-72N0D ~/code/azure-sdk-for-python/sdk/ml/azure-ai-ml/azure/ai/ml/_restclient [azure_ai_ml_tsp] % tsp-client update --local-spec-repo /home/kashifkhan/code/azure-rest-api-specs                                     Using output directory '/home/kashifkhan/code/azure-sdk-for-python/sdk/ml/azure-ai-ml/azure/ai/ml/_restclient'
 
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"Y888  88888P' 88888P"          "Y8888P 888 888  "Y8888  888  888  "Y888
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0.31.0
Found batch configuration with 7 directories
During batch processing will use local spec repo root with child library tsp-location.yaml data to resolve path to typespec project directory: /home/kashifkhan/code/azure-rest-api-specs
Processing batch directory: ./azure_ai_assets_v2024_04_01
Resolved local spec repo path using tsp-location.yaml directory: /home/kashifkhan/code/azure-rest-api-specs/specification/machinelearningservices/AzureAI.Assets
NOTE: A path to a local spec was provided, will generate based off of local files...
Local spec repo root is /home/kashifkhan/code/azure-rest-api-specs
Found emitter package @azure-tools/typespec-python@0.60.2
Skipping creation of tsp-client-metadata.yaml file.
Installing dependencies from npm...
(node:87604) [DEP0190] DeprecationWarning: Passing args to a child process with shell option true can lead to security vulnerabilities, as the arguments are not escaped, only concatenated.
(Use `node --trace-deprecation ...` to show where the warning was created)
npm error code 1
npm error path /home/kashifkhan/code/azure-sdk-for-python/sdk/ml/azure-ai-ml/azure/ai/ml/_restclient/azure_ai_assets_v2024_04_01/TempTypeSpecFiles/node_modules/@typespec/http-client-python
npm error command failed
npm error command sh -c tsx ./eng/scripts/setup/install.ts
npm error (node:87696) [DEP0190] DeprecationWarning: Passing args to a child process with shell option true can lead to security vulnerabilities, as the arguments are not escaped, only concatenated.
npm error (Use `node --trace-deprecation ...` to show where the warning was created)
npm error Traceback (most recent call last):
npm error   File "/home/kashifkhan/code/azure-sdk-for-python/sdk/ml/azure-ai-ml/azure/ai/ml/_restclient/azure_ai_assets_v2024_04_01/TempTypeSpecFiles/node_modules/@typespec/http-client-python/./eng/scripts/setup/install.py", line 19, in <module>
npm error     detect_package_manager()  # Just check if we have a package manager
npm error     ~~~~~~~~~~~~~~~~~~~~~~^^
npm error   File "/home/kashifkhan/code/azure-sdk-for-python/sdk/ml/azure-ai-ml/azure/ai/ml/_restclient/azure_ai_assets_v2024_04_01/TempTypeSpecFiles/node_modules/@typespec/http-client-python/eng/scripts/setup/package_manager.py", line 42, in detect_package_manager
npm error     if _check_command_available("uv"):
npm error        ~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^
npm error   File "/home/kashifkhan/code/azure-sdk-for-python/sdk/ml/azure-ai-ml/azure/ai/ml/_restclient/azure_ai_assets_v2024_04_01/TempTypeSpecFiles/node_modules/@typespec/http-client-python/eng/scripts/setup/package_manager.py", line 26, in _check_command_available
npm error     subprocess.run([command, "--version"], capture_output=True, check=True)
npm error     ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
npm error   File "/usr/lib/python3.13/subprocess.py", line 554, in run
npm error     with Popen(*popenargs, **kwargs) as process:
npm error          ~~~~~^^^^^^^^^^^^^^^^^^^^^^
npm error   File "/usr/lib/python3.13/subprocess.py", line 1039, in __init__
npm error     self._execute_child(args, executable, preexec_fn, close_fds,
npm error     ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
npm error                         pass_fds, cwd, env,
npm error                         ^^^^^^^^^^^^^^^^^^^
npm error     ...<5 lines>...
npm error                         gid, gids, uid, umask,
npm error                         ^^^^^^^^^^^^^^^^^^^^^^
npm error                         start_new_session, process_group)
npm error                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
npm error   File "/usr/lib/python3.13/subprocess.py", line 1991, in _execute_child
npm error     raise child_exception_type(errno_num, err_msg, err_filename)
npm error PermissionError: [Errno 13] Permission denied: 'uv'
npm error Python and package manager found but installation failed.
npm error A complete log of this run can be found in: /home/kashifkhan/.npm/_logs/2026-03-13T21_41_19_612Z-debug-0.log
Failed to process batch directory ./azure_ai_assets_v2024_04_01: Error: npm ci failed exited with code 1

quick repro

kashifkhan@CPC-kashi-72N0D ~  % strace -f -e trace=execve python3 -c "import subprocess; subprocess.run(['uv','--version'], capture_output=True)"
execve("/usr/bin/python3", ["python3", "-c", "import subprocess; subprocess.ru"...], 0x7ffc581e6a18 /* 39 vars */) = 0
strace: Process 10939 attached
[pid 10939] execve("/home/kashifkhan/.local/bin/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/home/kashifkhan/.aspire/bin/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/home/kashifkhan/go/bin/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/usr/local/go/bin/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/home/kashifkhan/.config/nvm/versions/node/v24.14.0/bin/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/home/kashifkhan/.cargo/bin/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/usr/local/sbin/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/usr/local/bin/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/usr/sbin/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/usr/bin/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/sbin/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/bin/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/usr/games/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/usr/local/games/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/usr/lib/wsl/lib/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/Windows/system32/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/Windows/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/Windows/System32/Wbem/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/Windows/System32/WindowsPowerShell/v1.0/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/Windows/System32/OpenSSH/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/Program Files/Microsoft SQL Server/150/Tools/Binn/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/.tools/dotnet/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/.tools/.npm-global/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/Users/vmadmin/AppData/Local/Microsoft/WindowsApps/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/Users/vmadmin/.dotnet/tools/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/Program Files/NuGet/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/Windows/system32/config/systemprofile/AppData/Local/Microsoft/WindowsApps/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 EACCES (Permission denied)
[pid 10939] execve("/mnt/c/Program Files/Microsoft Dev Box Agent/Scripts/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/WINDOWS/system32/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/WINDOWS/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/WINDOWS/System32/Wbem/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/WINDOWS/System32/WindowsPowerShell/v1.0/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/WINDOWS/System32/OpenSSH/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/Program Files/PowerShell/7/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/Program Files/Git/cmd/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/Program Files/Docker/Docker/resources/bin/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/Users/kashifkhan/AppData/Local/Microsoft/WindowsApps/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/Users/kashifkhan/AppData/Local/Programs/Microsoft VS Code/bin/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/Users/kashifkhan/AppData/Local/Programs/Microsoft VS Code Insiders/bin/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/mnt/c/Users/kashifkhan/AppData/Local/PowerToys/DSCModules/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/home/kashifkhan/.fzf/bin/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] execve("/home/kashifkhan/dotnet/uv", ["uv", "--version"], 0x7fff49cebf28 /* 39 vars */) = -1 ENOENT (No such file or directory)
[pid 10939] +++ exited with 255 +++
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=10939, si_uid=1000, si_status=255, si_utime=0, si_stime=0} ---
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/lib/python3.12/subprocess.py", line 548, in run
    with Popen(*popenargs, **kwargs) as process:
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/subprocess.py", line 1026, in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
  File "/usr/lib/python3.12/subprocess.py", line 1955, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
PermissionError: [Errno 13] Permission denied: 'uv'
+++ exited with 1 +++
kashifkhan@CPC-kashi-72N0D ~  %

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/@typespec/http-client-python@10084

commit: c6808b0

[azure-sdk]

You can try these changes here

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[github-actions]

All changed packages have been documented.

• ✅ @typespec/http-client-python

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@typespec/http-client-python - fix ✏️

Fix PermissionError when detecting package manager on WSL