use uv to bootstrap the host system Python environment (#892)

jjhelmus · web-flow · commit fa176fef605f · 2025-12-02T13:22:23.000-06:00
Add a new build script which uses uv to bootstrap the Python environment
on the host and runs the build.

To use this new script on a host with uv installed use:
```
./build-uv.py 
```
diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
@@ -71,10 +71,10 @@ jobs:
         with:
           persist-credentials: false
 
-      - name: Install Python
-        uses: actions/setup-python@e797f83bcb11b83ae66e0230d6156d7c80228e7c # v6.0.0
+      - name: Set up uv
+        uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
         with:
-          python-version: "3.11"
+          enable-cache: false
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@e468171a9de216ec08956ac3ada2f0791b6bd435 # v3.11.1
@@ -88,7 +88,7 @@ jobs:
 
       - name: Generate Dockerfiles
         run: |
-          ./build-linux.py --make-target empty
+          ./build-uv.py --make-target empty
           repo_name=$(echo "${GITHUB_REPOSITORY,,}" | sed 's|\.|_|g')
           git_ref_name=$(echo "${GITHUB_REF_NAME,,}" | sed 's|[^a-z0-9_-]|_|g')
           echo "REPO_NAME=${repo_name}" >> "${GITHUB_ENV}"
@@ -150,8 +150,10 @@ jobs:
           fetch-depth: 0
           persist-credentials: false
 
-      - name: Set up Python
-        uses: astral-sh/setup-uv@38f3f104447c67c051c4a08e39b64a148898af3a # v4.2.0
+      - name: Set up uv
+        uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
+        with:
+          enable-cache: false
 
       - name: Get pull request labels
         id: get-labels
@@ -222,10 +224,10 @@ jobs:
           fetch-depth: 0
           persist-credentials: false
 
-      - name: Install Python
-        uses: actions/setup-python@e797f83bcb11b83ae66e0230d6156d7c80228e7c # v6.0.0
+      - name: Set up uv
+        uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
         with:
-          python-version: "3.11"
+          enable-cache: false
 
       - name: Download pythonbuild
         uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0 # v5.0.0
@@ -265,12 +267,12 @@ jobs:
         if: ${{ ! matrix.dry-run }}
         run: |
           # Do empty target so all generated files are touched.
-          ./build-linux.py --make-target empty
+          ./build-uv.py --make-target empty
 
           # Touch mtimes of all images so they are newer than autogenerated files above.
           touch build/image-*
 
-          ./build-linux.py --target-triple ${MATRIX_TARGET_TRIPLE} --python cpython-${MATRIX_PYTHON} --options ${MATRIX_BUILD_OPTIONS}
+          ./build-uv.py --target-triple ${MATRIX_TARGET_TRIPLE} --python cpython-${MATRIX_PYTHON} --options ${MATRIX_BUILD_OPTIONS}
         env:
           MATRIX_TARGET_TRIPLE: ${{ matrix.target_triple }}
           MATRIX_PYTHON: ${{ matrix.python }}
@@ -330,10 +332,10 @@ jobs:
           fetch-depth: 0
           persist-credentials: false
 
-      - name: Install Python
-        uses: actions/setup-python@e797f83bcb11b83ae66e0230d6156d7c80228e7c # v6.0.0
+      - name: Set up uv
+        uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
         with:
-          python-version: "3.11"
+          enable-cache: false
 
       - name: Download pythonbuild
         uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0 # v5.0.0
@@ -373,12 +375,12 @@ jobs:
         if: ${{ ! matrix.dry-run }}
         run: |
           # Do empty target so all generated files are touched.
-          ./build-linux.py --make-target empty
+          ./build-uv.py --make-target empty
 
           # Touch mtimes of all images so they are newer than autogenerated files above.
           touch build/image-*
 
-          ./build-linux.py --target-triple ${MATRIX_TARGET_TRIPLE} --python cpython-${MATRIX_PYTHON} --options ${MATRIX_BUILD_OPTIONS}
+          ./build-uv.py --target-triple ${MATRIX_TARGET_TRIPLE} --python cpython-${MATRIX_PYTHON} --options ${MATRIX_BUILD_OPTIONS}
         env:
           MATRIX_TARGET_TRIPLE: ${{ matrix.target_triple }}
           MATRIX_PYTHON: ${{ matrix.python }}
diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
@@ -63,8 +63,10 @@ jobs:
           fetch-depth: 0
           persist-credentials: false
 
-      - name: Set up Python
-        uses: astral-sh/setup-uv@38f3f104447c67c051c4a08e39b64a148898af3a # v4.2.0
+      - name: Set up uv
+        uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
+        with:
+          enable-cache: false
 
       - name: Get pull request labels
         id: get-labels
@@ -128,10 +130,10 @@ jobs:
           fetch-depth: 0
           persist-credentials: false
 
-      - name: Install Python
-        uses: actions/setup-python@e797f83bcb11b83ae66e0230d6156d7c80228e7c # v6.0.0
+      - name: Set up uv
+        uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
         with:
-          python-version: "3.11"
+          enable-cache: false
 
       - name: Download pythonbuild
         uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0 # v5.0.0
@@ -142,7 +144,7 @@ jobs:
       - name: Build
         if: ${{ ! matrix.dry-run }}
         run: |
-          ./build-macos.py --target-triple ${MATRIX_TARGET_TRIPLE} --python cpython-${MATRIX_PYTHON} --options ${MATRIX_BUILD_OPTIONS}
+          ./build-uv.py --target-triple ${MATRIX_TARGET_TRIPLE} --python cpython-${MATRIX_PYTHON} --options ${MATRIX_BUILD_OPTIONS}
         env:
           MATRIX_TARGET_TRIPLE: ${{ matrix.target_triple }}
           MATRIX_PYTHON: ${{ matrix.python }}
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
@@ -63,8 +63,10 @@ jobs:
           fetch-depth: 0
           persist-credentials: false
 
-      - name: Set up Python
-        uses: astral-sh/setup-uv@38f3f104447c67c051c4a08e39b64a148898af3a # v4.2.0
+      - name: Set up uv
+        uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
+        with:
+          enable-cache: false
 
       - name: Get pull request labels
         id: get-labels
@@ -134,10 +136,10 @@ jobs:
         with:
           packages: autoconf automake libtool
 
-      - name: Install Python
-        uses: actions/setup-python@e797f83bcb11b83ae66e0230d6156d7c80228e7c # v6.0.0
+      - name: Set up uv
+        uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
         with:
-          python-version: "3.12"
+          enable-cache: false
 
       - name: Download pythonbuild Executable
         uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0 # v5.0.0
@@ -148,14 +150,14 @@ jobs:
       # don't get compiled properly.
       - name: Bootstrap Python environment
         run: |
-          py.exe -3.12 build-windows.py --help
+          uv run build-uv.py --help
 
       - name: Build
         if: ${{ ! matrix.dry-run }}
         shell: cmd
         run: |
           call "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\Build\%MATRIX_VCVARS%"
-          py.exe -3.12 build-windows.py --python cpython-%MATRIX_PYTHON% --sh c:\cygwin\bin\sh.exe --options %MATRIX_BUILD_OPTIONS%
+          uv run build-uv.py --python cpython-%MATRIX_PYTHON% --sh c:\cygwin\bin\sh.exe --options %MATRIX_BUILD_OPTIONS%
         env:
           MATRIX_VCVARS: ${{ matrix.vcvars }}
           MATRIX_PYTHON: ${{ matrix.python }}
diff --git a/.python-version b/.python-version
@@ -0,0 +1 @@
+3.13
diff --git a/build-uv.py b/build-uv.py
@@ -0,0 +1,46 @@
+#!/usr/bin/env -S uv run
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+import os
+import pathlib
+import platform
+import subprocess
+import sys
+
+ROOT = pathlib.Path(os.path.abspath(__file__)).parent
+
+
+def run():
+    env = dict(os.environ)
+    env["PYTHONUNBUFFERED"] = "1"
+    python = sys.executable
+    system = platform.system()
+
+    if system == "Darwin" or system == "Linux":
+        args = [
+            python,
+            "build-main.py",
+            *sys.argv[1:],
+        ]
+        make_dir = ROOT / "cpython-unix"
+        os.chdir(make_dir)
+        return os.execve(python, args, env)
+    elif system == "Windows":
+        args = [
+            python,
+            "build.py",
+            *sys.argv[1:],
+        ]
+        cwd = str(ROOT / "cpython-windows")
+        return subprocess.run(args, cwd=cwd, env=env, check=True, bufsize=0)
+    else:
+        raise Exception(f"Unsupported host system: {system}")
+
+
+if __name__ == "__main__":
+    try:
+        run()
+    except subprocess.CalledProcessError as e:
+        sys.exit(e.returncode)
diff --git a/cpython-windows/build.py b/cpython-windows/build.py
@@ -1512,7 +1512,8 @@ def build_cpython(
                 p for p in env["PATH"].split(";") if p != str(BUILD / "venv" / "bin")
             ]
             env["PATH"] = ";".join(paths)
-            del env["PYTHONPATH"]
+            if "PYTHONPATH" in env:
+                del env["PYTHONPATH"]
 
             env["PYTHONHOME"] = str(cpython_source_path)
 
@@ -1974,6 +1975,7 @@ def main() -> None:
             release_tag = release_tag_from_git()
 
         # Create, e.g., `cpython-3.10.13+20240224-x86_64-pc-windows-msvc-pgo.tar.zst`.
+        DIST.mkdir(exist_ok=True)
         compress_python_archive(
             tar_path,
             DIST,
diff --git a/pyproject.toml b/pyproject.toml
@@ -0,0 +1,25 @@
+[project]
+name = "python-build-standalone"
+version = "0.1.0"
+description = "Produces standalone, highly-redistributable builds of Python."
+readme = "README.rst"
+requires-python = ">=3.10"
+dependencies = [
+    "docker>=7.1.0",
+    "jinja2>=3.1.5",
+    "jsonschema>=4.23.0",
+    "pygithub>=2.6.1 ; platform_machine != 'aarch64' or sys_platform != 'win32'",
+    "pyyaml>=6.0.2",
+    "six>=1.17.0",
+    "tomli>=2.2.1",
+    "typing-extensions>=4.14.1",
+    "zstandard>=0.23.0",
+]
+
+[build-system]
+requires = ["uv_build>=0.9.12,<0.10.0"]
+build-backend = "uv_build"
+
+[tool.uv.build-backend]
+module-name = "pythonbuild"
+module-root = ""
diff --git a/uv.lock b/uv.lock
