Merge pull request #749 from pypa/docs-setup

docs: Rework the setup page to include information about local builds before going to CI
pypa · Sep 9, 2021 · f43b403 · f43b403
2 parents 02652e6 + 326a9a9
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diff --git a/docs/extra.css b/docs/extra.css
@@ -10,6 +10,14 @@ p {
     line-height: 26px;
 }
 
+pre {
+  margin: 1em 0;
+}
+
+pre:first-child {
+  margin-top: 0;
+}
+
 code {
     font-size: 85%;
     background-color: rgba(27,31,35,.05);
@@ -22,6 +30,7 @@ code {
 
 code, pre, tt {
     font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, monospace;
+    line-height: 1.4;
 }
 
 pre code, pre code.hljs {
@@ -216,6 +225,3 @@ h1, h2, h3, h4, h5, h6 {
   padding-right: 0;
   margin-bottom: 0.5em;
 }
-.tabs.examples pre:first-child {
-  margin-top: 0;
-}
diff --git a/docs/faq.md b/docs/faq.md
@@ -2,35 +2,23 @@
 title: Tips and tricks
 ---
 
-### Troubleshooting
-
-If your wheel didn't compile, check the list below for some debugging tips.
-
-- A mistake in your config. To quickly test your config without doing a git push and waiting for your code to build on CI, you can test the Linux build in a Docker container. On Mac or Linux, with Docker running, try `cibuildwheel --platform linux`. You'll have to bring your config into the current environment first.
-
-- Missing dependency. You might need to install something on the build machine. You can do this in `.travis.yml`, `appveyor.yml`, or `.circleci/config.yml`, with apt-get, brew or choco. Given how the Linux build works, you'll need to use the [`CIBW_BEFORE_BUILD`](options.md#before-build) option.
-
-- Windows: missing C feature. The Windows C compiler doesn't support C language features invented after 1990, so you'll have to backport your C code to C90. For me, this mostly involved putting my variable declarations at the top of the function like an animal.
-
-- MacOS: calling cibuildwheel from a python3 script and getting a `ModuleNotFoundError`? Due to a (fixed) [bug](https://bugs.python.org/issue22490) in CPython, you'll need to [unset the `__PYVENV_LAUNCHER__` variable](https://github.com/pypa/cibuildwheel/issues/133#issuecomment-478288597) before activating a venv.
-
-### Building Python 2.7 / PyPy2 wheels
-
-See the [cibuildwheel version 1 docs](https://cibuildwheel.readthedocs.io/en/1.x/) for information about building Python 2.7 or PyPy2 wheels. There are lots of tricks and workaround there that are no longer required for Python 3 in cibuildwheel 2.
+## Tips
 
 ### Linux builds on Docker
 
 Linux wheels are built in the [`manylinux` docker images](https://github.com/pypa/manylinux) to provide binary compatible wheels on Linux, according to [PEP 571](https://www.python.org/dev/peps/pep-0571/). Because of this, when building with `cibuildwheel` on Linux, a few things should be taken into account:
 
-- Programs and libraries are not installed on the Travis CI Ubuntu host, but rather should be installed inside of the Docker image (using `yum` for `manylinux2010` or `manylinux2014`, and `apt-get` for `manylinux_2_24`) or manually. The same goes for environment variables that are potentially needed to customize the wheel building. `cibuildwheel` supports this by providing the `CIBW_ENVIRONMENT` and `CIBW_BEFORE_BUILD` options to setup the build environment inside the running Docker image. See [the options docs](options.md#build-environment) for details on these options.
+-   Programs and libraries are not installed on the CI runner host, but rather should be installed inside of the Docker image - using `yum` for `manylinux2010` or `manylinux2014`, and `apt-get` for `manylinux_2_24`, or manually. The same goes for environment variables that are potentially needed to customize the wheel building.
 
-- The project directory is mounted in the running Docker instance as `/project`, the output directory for the wheels as `/output`. In general, this is handled transparently by `cibuildwheel`. For a more finegrained level of control however, the root of the host file system is mounted as `/host`, allowing for example to access shared files, caches, etc. on the host file system.  Note that this is not available on CircleCI due to their Docker policies.
+    `cibuildwheel` supports this by providing the [`CIBW_ENVIRONMENT`](options.md#environment) and [`CIBW_BEFORE_ALL`](options.md#before-all) options to setup the build environment inside the running Docker image.
 
-- Alternative dockers images can be specified with the `CIBW_MANYLINUX_X86_64_IMAGE`, `CIBW_MANYLINUX_I686_IMAGE`, and `CIBW_MANYLINUX_PYPY_X86_64_IMAGE` options to allow for a custom, preconfigured build environment for the Linux builds. See [options](options.md#manylinux-image) for more details.
+-   The project directory is mounted in the running Docker instance as `/project`, the output directory for the wheels as `/output`. In general, this is handled transparently by `cibuildwheel`. For a more finegrained level of control however, the root of the host file system is mounted as `/host`, allowing for example to access shared files, caches, etc. on the host file system.  Note that `/host` is not available on CircleCI due to their Docker policies.
+
+-   Alternative Docker images can be specified with the `CIBW_MANYLINUX_*_IMAGE` options to allow for a custom, preconfigured build environment for the Linux builds. See [options](options.md#manylinux-image) for more details.
 
 ### Building macOS wheels for Apple Silicon {: #apple-silicon}
 
-`cibuildwheel` supports cross-compiling `universal2` and `arm64` wheels on `x86_64` runners. With the introduction of Apple Silicon, you now have several choices for wheels for Python 3.9+:
+`cibuildwheel` supports cross-compiling `universal2` and `arm64` wheels on `x86_64` runners. With the introduction of Apple Silicon, you now have several choices for wheels for Python 3.8+:
 
 #### `x86_64`
 
@@ -89,6 +77,7 @@ by default, and require opt-in by setting `CIBW_ARCHS_MACOS`.
 Here's an example GitHub Actions workflow with a job that builds for Apple Silicon:
 
 > .github/workflows/build_macos.yml
+
 ```yml
 {% include "../examples/github-apple-silicon.yml" %}
 ```
@@ -114,33 +103,6 @@ Linux), and the other architectures are emulated automatically.
 {% include "../examples/github-with-qemu.yml" %}
 ```
 
-### Building Apple Silicon wheels on Intel {: #apple-silicon}
-
-`cibuildwheel` supports cross-compiling `universal2` and `arm64` wheels on `x86_64` runners.
-
-These wheels are not built by default, but can be enabled by setting the [`CIBW_ARCHS_MACOS` option](options.md#archs) to `x86_64 arm64 universal2`. Cross-compilation is provided by the Xcode toolchain.
-
-!!! important
-    When cross-compiling on Intel, it is not possible to test `arm64` and the `arm64` part of a `universal2` wheel.
-
-    `cibuildwheel` will raise a warning to notify you of this - these warnings be be silenced by skipping testing on these platforms: `CIBW_TEST_SKIP: *_arm64 *_universal2:arm64`.
-
-Hopefully, this is a temporary situation. Once we have widely available Apple Silicon CI runners, we can build and test `arm64` and `universal2` wheels more natively. That's why `universal2` wheels are not yet built by default, and require opt-in by setting `CIBW_ARCHS_MACOS`.
-
-!!! note
-    Your runner image needs Xcode Command Line Tools 12.2 or later to build `universal2` and `arm64`.
-
-    So far, only CPython 3.9 supports `universal2` and `arm64` wheels.
-
-Here's an example GitHub Actions workflow with a job that builds for Apple Silicon:
-
-> .github/workflows/build_macos.yml
-
-```yml
-{% include "../examples/github-apple-silicon.yml" %}
-```
-
-
 ### Building packages with optional C extensions
 
 `cibuildwheel` defines the environment variable `CIBUILDWHEEL` to the value `1` allowing projects for which the C extension is optional to make it mandatory when building wheels.
@@ -155,51 +117,6 @@ myextension = Extension(
 )
 ```
 
-### 'No module named XYZ' errors after running cibuildwheel on macOS
-
-`cibuildwheel` on Mac installs the distributions from Python.org system-wide during its operation. This is necessary, but it can cause some confusing errors after cibuildwheel has finished.
-
-Consider the build script:
-
-```bash
-python3 -m pip install twine cibuildwheel
-python3 -m cibuildwheel --output-dir wheelhouse
-python3 -m twine upload wheelhouse/*.whl
-# error: no module named 'twine'
-```
-
-This doesn't work because while `cibuildwheel` was running, it installed a few new versions of 'python3', so the `python3` run on line 3 isn't the same as the `python3` that ran on line 1.
-
-Solutions to this vary, but the simplest is to install tools immediately before they're used:
-
-```bash
-python3 -m pip install cibuildwheel
-python3 -m cibuildwheel --output-dir wheelhouse
-python3 -m pip install twine
-python3 -m twine upload wheelhouse/*.whl
-```
-
-### 'ImportError: DLL load failed: The specific module could not be found' error on Windows
-
-Visual Studio and MSVC link the compiled binary wheels to the Microsoft Visual C++ Runtime. Normally, these are included with Python, but when compiling with a newer version of Visual Studio, it is possible users will run into problems on systems that do not have these runtime libraries installed. The solution is to ask users to download the corresponding Visual C++ Redistributable from the [Microsoft website](https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads) and install it. Since a Python installation normally includes these VC++ Redistributable files for [the version of the MSVC compiler used to compile Python](https://wiki.python.org/moin/WindowsCompilers), this is typically only a problem when compiling a Python C extension with a newer compiler.
-
-Additionally, Visual Studio 2019 started linking to an even newer DLL, `VCRUNTIME140_1.dll`, besides the `VCRUNTIME140.dll` that is included with recent Python versions (starting from Python 3.5; see [here](https://wiki.python.org/moin/WindowsCompilers) for more details on the corresponding Visual Studio & MSVC versions used to compile the different Python versions). To avoid this extra dependency on `VCRUNTIME140_1.dll`, the [`/d2FH4-` flag](https://devblogs.microsoft.com/cppblog/making-cpp-exception-handling-smaller-x64/) can be added to the MSVC invocations (check out [this issue](https://github.com/pypa/cibuildwheel/issues/423) for details and references).
-
-To add the `/d2FH4-` flag to a standard `setup.py` using `setuptools`, the `extra_compile_args` option can be used:
-
-```python
-    ext_modules=[
-        Extension(
-            'c_module',
-            sources=['extension.c'],
-            extra_compile_args=['/d2FH4-'] if sys.platform == 'win32' else []
-        )
-    ],
-```
-
-To investigate the dependencies of a C extension (i.e., the `.pyd` file, a DLL in disguise) on Windows, [Dependency Walker](http://www.dependencywalker.com/) is a great tool.
-
-
 ### Automatic updates {: #automatic-updates}
 
 Selecting a moving target (like the latest release) is generally a bad idea in CI. If something breaks, you can't tell whether it was your code or an upstream update that caused the breakage, and in a worse-case scenario, it could occur during a release.
@@ -251,3 +168,133 @@ updates:
 ```
 
 This will also try to update other pins in all requirement files, so be sure you want to do that. The only control you have over the files used is via the directory option.
+
+
+### Alternatives to cibuildwheel options {: #cibw-options-alternatives}
+
+cibuildwheel provides lots of opportunities to configure the build
+environment. However, you  might consider adding this build configuration into
+the package itself - in general, this is preferred, because users of your
+package 'sdist' will also benefit.
+
+#### Missing build dependencies {: #cibw-options-alternatives-deps}
+
+If your build needs Python dependencies, rather than using CIBW_BEFORE_BUILD, it's best to add these to the
+[`build-system.requires`](https://www.python.org/dev/peps/pep-0518/#build-system-table)
+section of your pyproject.toml. For example, if your project requires Cython
+to build, your pyproject.toml might include a section like this:
+
+```toml
+[build-system]
+requires = [
+    "setuptools>=42",
+    "wheel",
+    "Cython",
+]
+
+build-backend = "setuptools.build_meta"
+```
+
+#### Actions you need to perform before building
+
+You might need to run some other commands before building, like running a
+script that performs codegen or downloading some data that's not stored in
+your source tree.
+
+Rather than using CIBW_BEFORE_ALL or CIBW_BEFORE_BUILD, you could incorporate
+these steps into your package's build process. For example, if you're using
+setuptools, you can add steps to your package's `setup.py` using a structure
+like this:
+
+    ```python
+    import subprocess
+    import setuptools
+    import setuptools.command.build_py
+
+
+    class BuildPyCommand(setuptools.command.build_py.build_py):
+      """Custom build command."""
+
+      def run(self):
+        # your custom build steps here
+        # e.g.
+        #   subprocess.run(['python', 'scripts/my_custom_script.py'], check=True)
+        setuptools.command.build_py.build_py.run(self)
+
+
+    setuptools.setup(
+        cmdclass={
+            'build_py': BuildPyCommand,
+        },
+        # Usual setup() args.
+        # ...
+    )
+    ```
+
+#### Compiler flags
+
+Your build might need some compiler flags to be set through environment variables.
+Consider incorporating these into your package, for example, in `setup.py` using [`extra_compile_args` or
+`extra_link_args`](https://docs.python.org/3/distutils/setupscript.html#other-options).
+
+### Python 2.7 / PyPy2 wheels
+
+See the [cibuildwheel version 1 docs](https://cibuildwheel.readthedocs.io/en/1.x/) for information about building Python 2.7 or PyPy2 wheels. There are lots of tricks and workaround there that are no longer required for Python 3 in cibuildwheel 2.
+
+## Troubleshooting
+
+If your wheel didn't compile, you might have a mistake in your config.
+
+To quickly test your config without doing a git push and waiting for your code to build on CI, you can [test the Linux build in a local Docker container](setup.md#local).
+
+### Missing dependencies
+
+You might need to install something on the build machine. You can do this with apt/yum, brew or choco, using the [`CIBW_BEFORE_ALL`](options.md#before-all) option. Or, for a Python dependency, consider [adding it to pyproject.toml](#cibw-options-alternatives-deps).
+
+### ModuleNotFoundError on macOS
+
+Calling cibuildwheel from a python3 script and getting a `ModuleNotFoundError`? Due to a (fixed) [bug](https://bugs.python.org/issue22490) in CPython, you'll need to [unset the `__PYVENV_LAUNCHER__` variable](https://github.com/pypa/cibuildwheel/issues/133#issuecomment-478288597) before activating a venv.
+
+### 'No module named XYZ' errors after running cibuildwheel on macOS
+
+`cibuildwheel` on Mac installs the distributions from Python.org system-wide during its operation. This is necessary, but it can cause some confusing errors after cibuildwheel has finished.
+
+Consider the build script:
+
+```bash
+python3 -m pip install twine cibuildwheel
+python3 -m cibuildwheel --output-dir wheelhouse
+python3 -m twine upload wheelhouse/*.whl
+# error: no module named 'twine'
+```
+
+This doesn't work because while `cibuildwheel` was running, it installed a few new versions of 'python3', so the `python3` run on line 3 isn't the same as the `python3` that ran on line 1.
+
+Solutions to this vary, but the simplest is to install tools immediately before they're used:
+
+```bash
+python3 -m pip install cibuildwheel
+python3 -m cibuildwheel --output-dir wheelhouse
+python3 -m pip install twine
+python3 -m twine upload wheelhouse/*.whl
+```
+
+### 'ImportError: DLL load failed: The specific module could not be found' error on Windows
+
+Visual Studio and MSVC link the compiled binary wheels to the Microsoft Visual C++ Runtime. Normally, these are included with Python, but when compiling with a newer version of Visual Studio, it is possible users will run into problems on systems that do not have these runtime libraries installed. The solution is to ask users to download the corresponding Visual C++ Redistributable from the [Microsoft website](https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads) and install it. Since a Python installation normally includes these VC++ Redistributable files for [the version of the MSVC compiler used to compile Python](https://wiki.python.org/moin/WindowsCompilers), this is typically only a problem when compiling a Python C extension with a newer compiler.
+
+Additionally, Visual Studio 2019 started linking to an even newer DLL, `VCRUNTIME140_1.dll`, besides the `VCRUNTIME140.dll` that is included with recent Python versions (starting from Python 3.5; see [here](https://wiki.python.org/moin/WindowsCompilers) for more details on the corresponding Visual Studio & MSVC versions used to compile the different Python versions). To avoid this extra dependency on `VCRUNTIME140_1.dll`, the [`/d2FH4-` flag](https://devblogs.microsoft.com/cppblog/making-cpp-exception-handling-smaller-x64/) can be added to the MSVC invocations (check out [this issue](https://github.com/pypa/cibuildwheel/issues/423) for details and references).
+
+To add the `/d2FH4-` flag to a standard `setup.py` using `setuptools`, the `extra_compile_args` option can be used:
+
+```python
+    ext_modules=[
+        Extension(
+            'c_module',
+            sources=['extension.c'],
+            extra_compile_args=['/d2FH4-'] if sys.platform == 'win32' else []
+        )
+    ],
+```
+
+To investigate the dependencies of a C extension (i.e., the `.pyd` file, a DLL in disguise) on Windows, [Dependency Walker](http://www.dependencywalker.com/) is a great tool.