Original issue. Resolved in the reported scope. sysconfig.get_config_var("Py_GIL_DISABLED") is defined as 1 in the verified POSIX RustPython build.

• Source and standard library: f39b054b9c8c.
• Verified October 5, 2026 on macOS 26.5.2 ARM64.
• RustPython: 0.6.1, Python 3.14.0.alpha; x86_64 through Rosetta.
• Comparison: CPython 3.14.6 ARM64.

Use absolute paths for the variables below:

• RP: the RustPython executable for this commit.
• CP: the CPython 3.14.6 executable.
• SRC: the source directory at this commit, including its matching Lib.
• CASE: the directory containing the files shown below.

Shell variables replace recorded absolute paths. Export them so the Python inputs can use them:

export RP CP SRC CASE
unset PYTHONPATH PYTHONHOME PYTHONWARNINGS PYTHONSTARTUP
export PYTHONDONTWRITEBYTECODE=1

export LC_ALL=en_US.UTF-8

Save as probe-6429.py.

import sys, sysconfig

value = sysconfig.get_config_var("Py_GIL_DISABLED")
print(value)
print("type", type(value).__name__)
print("implementation", sys.implementation.name)
print("platform", sys.platform)
print("gil_enabled", getattr(sys, "_is_gil_enabled", lambda: "unavailable")())

cd "$SRC"

RustPython:

RUSTPYTHONPATH="$SRC/Lib" "$RP" -B -S "$CASE/probe-6429.py"

CPython:

"$CP" -B -S "$CASE/probe-6429.py"

Expected: The tested RustPython build must expose its build-time Py_GIL_DISABLED setting instead of None.

Exit code: 0. No timeout.

stdout:

1
type int
implementation rustpython
platform darwin
gil_enabled False

stderr:

No output.

Exit code: 0. No timeout.

stdout:

0
type int
implementation cpython
platform darwin
gil_enabled True

stderr:

No output.

Previously recorded at e227956a58f0; exit code 0. This run was not repeated alongside the current results. Historical inputs may differ from the expanded checks above.

stdout:

None

Historical output excerpt; runner metadata and repeated shutdown warnings are omitted.

PR #6428: expose the build-time Py_GIL_DISABLED value.

CPython can legitimately return a different value. This is not proof of full free-threading or C-extension compatibility.

First fixing commit: not established.

Recorded executable SHA-256 values:

• RustPython: d57429291c1011b8b311758237cb66a6fecc22f8647ff14094f5c00fb489d871.

• CPython: 58eea46bd68c84e30980ca1133d1b0efb139c878a4934a519dba0846b74069ef.

• CPython command, environment and output record.

• RustPython command, environment and output record.

• Executed source.

• Scope and complete execution inventory.

• Historical record.

AI assistance: OpenAI Codex.