`uv python install 3.13t` issues on Windows and Linux

[colesbury]

Nice work! This is my favorite way to install Python. I ran into two issues:

On Windows, uv python install 3.13t doesn't seem to install a free-threaded build.

> uv python install 3.13t
> uv python list
cpython-3.13.0-windows-x86_64-none     AppData\Roaming\uv\python\cpython-3.13.0+freethreaded-windows-x86_64-none\python.exe

> uv run -p 3.13t python -c "import sysconfig; print(sysconfig.get_config_var('Py_GIL_DISABLED'))"
0

On Linux, uv python install 3.13t installs a debug build:

> uv run -p 3.13t python -c "import sysconfig; print(sysconfig.get_config_var('CFLAGS'))"
-fno-strict-overflow -Wsign-compare -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer -g -Og -Wall  -fPIC

Whereas 3.13 (GIL) is an optimized build, like I'd expect:

> uv run -p 3.13 python -c "import sysconfig; print(sysconfig.get_config_var('CFLAGS'))"
-fno-strict-overflow -Wsign-compare -Wunreachable-code -DNDEBUG -g -O3 -Wall  -fPIC

[zanieb]

Thanks for the report! I'll look into this.

[colesbury]

In case this is helpful, for the free threaded Windows build:

• If you use the batch scripts (e.g., PCBuild/build.bat), you should pass --disable-gil
• If you use MSBuild (on PCBuild/pcbuild.proj), you should pass /p:DisableGil=true
• IIRC, MSBuild copies PC/pyconfig.h.in to PC/pyconfig.h and replaces the /* #define Py_GIL_DISABLED 1 */ with #define Py_GIL_DISABLED 1

[colesbury]

Oh, I see now you already have a PR in progress: astral-sh/python-build-standalone#368.

[zanieb]

Yep! Sorry about that. I should have the fix out soon — just takes a while to build all the distributions over there.

[charliermarsh]

@zanieb -- Is this one closed out given your recent merge?

[zanieb]

Yep!

Closed by #8196 and #8268

Will be released soon.

[farzbood]

based on Python 3.13.0 docs

To check if the current interpreter supports free-threading, python -VV and sys.version contain “experimental free-threading build”.
but the managed python 3.13t installed by uv python install 3.13t doesn't show the expected output!

(edit):
how to remove/unistall a managed python version? deleting the installation path take care of it?