set -e

cd /home/user/RustPython

echo "=== RustPython dev environment setup ==="

CURRENT_PY=$(python3 --version 2>&1 | grep -oP '\d+\.\d+')

if [ "$(printf '%s\n' "3.13" "$CURRENT_PY" | sort -V | head -1)" != "3.13" ]; then

echo "Upgrading python3 default to 3.13..."

# Find best available Python >= 3.13

TARGET=""

for ver in python3.15 python3.14 python3.13; do

if command -v "$ver" &>/dev/null; then

TARGET=$(command -v "$ver")

break

fi

done

if [ -n "$TARGET" ]; then

# Override /usr/local/bin/python3 if it exists and is outdated

if [ -e /usr/local/bin/python3 ]; then

sudo ln -sf "$TARGET" /usr/local/bin/python3

fi

# Also set /usr/bin via update-alternatives

sudo update-alternatives --install /usr/bin/python3 python3 "$TARGET" 3 2>/dev/null || true

sudo update-alternatives --set python3 "$TARGET" 2>/dev/null || true

echo "python3 now: $(python3 --version)"

else

echo "WARNING: No Python 3.13+ found. scripts/update_lib may not work."

fi

echo "python3 already >= 3.13: $(python3 --version)"

PYTHON_VERSION="v3.15.0"

if [ ! -e "cpython" ]; then

git clone --depth 1 --branch "$PYTHON_VERSION" https://github.com/python/cpython.git cpython

elif [ ! -d "cpython/.git" ] || [ ! -d "cpython/Lib" ] ||

[ "$(git -C cpython rev-parse HEAD)" != "$(git -C cpython rev-parse --verify "$PYTHON_VERSION^{commit}" 2>/dev/null)" ] ||

[ -n "$(git -C cpython status --porcelain)" ]; then

echo "ERROR: cpython must be a clean checkout of $PYTHON_VERSION. Move the existing directory aside and rerun." >&2

exit 1

echo "CPython $PYTHON_VERSION source already present."

echo "=== Setup complete ==="