Our package build process currently has a significant flaw: we first run `setup.py`, recording all compilation commands, then we rewrite these compilation commands to invoke `emcc` and replay them, and then we pray that the cross compiled executables ended up in the right place to go into the wheel. This is not a good strategy because the build script is allowed to implement arbitrary logic, and if it moves, renames, etc any of the output files then we lose track of them. This has repeatedly caused difficulty for us.

However, we also make no particularly significant use of the two pass approach. We can just do the simpler thing: capture the compiler commands as they occur, modify them as needed, and then run the fixed command.

I also added a patch to fix the numpy feature detection for wasm so that we don't have to include `_npyconfig.h` and `config.h`, numpy can generate them in the way it would for a native build. I opened a numpy PR that would fix the detection for us upstream:
https://github.com/numpy/numpy/pull/21154

This clears the way for us to switch to using pypa/build (as @henryiii has suggested) by removing our dependence on specific setuptools behavior.

This is on top of #2238.
No replay. Our package build process currently has a significant flaw: we first run `setup.py`, recording all compilation commands, then we rewrite these compilation commands to invoke `emcc` and replay them, and then we pray that the cross compiled executables ended up in the right place to go into the wheel. This is not a good strategy because the build script is allowed to implement arbitrary logic, and if it moves, renames, etc any of the output files then we lose track of them. This has repeatedly caused difficulty for us.

However, we also make no particularly significant use of the two pass approach. We can just do the simpler thing: capture the compiler commands as they occur, modify them as needed, and then run the fixed command.

I also added a patch to fix the numpy feature detection for wasm so that we don't have to include `_npyconfig.h` and `config.h`, numpy can generate them in the way it would for a native build. I opened a numpy PR that would fix the detection for us upstream:
https://github.com/numpy/numpy/pull/21154

This clears the way for us to switch to using pypa/build (as @henryiii has suggested) by removing our dependence on specific setuptools behavior.

This is on top of #2238.
from typing import Dict, Iterable, List

from ..._vendor.pkg_resources import yield_lines


class DictMetadata:
    """IMetadataProvider that reads metadata files from a dictionary."""

    def __init__(self, metadata):
        # type: (Dict[str, bytes]) -> None
        self._metadata = metadata

    def has_metadata(self, name):
        # type: (str) -> bool
        return name in self._metadata

    def get_metadata(self, name):
        # type: (str) -> str
        try:
            return self._metadata[name].decode()
        except UnicodeDecodeError as e:
            # Mirrors handling done in pkg_resources.NullProvider.
            e.reason += f" in {name} file"
            raise

    def get_metadata_lines(self, name):
        # type: (str) -> Iterable[str]
        return yield_lines(self.get_metadata(name))

    def metadata_isdir(self, name):
        # type: (str) -> bool
        return False

    def metadata_listdir(self, name):
        # type: (str) -> List[str]
        return []

    def run_script(self, script_name, namespace):
        # type: (str, str) -> None
        pass

from typing import Dict, Iterable, List

from ..._vendor.pkg_resources import yield_lines


class DictMetadata:
    """IMetadataProvider that reads metadata files from a dictionary."""

    def __init__(self, metadata):
        # type: (Dict[str, bytes]) -> None
        self._metadata = metadata

    def has_metadata(self, name):
        # type: (str) -> bool
        return name in self._metadata

    def get_metadata(self, name):
        # type: (str) -> str
        try:
            return self._metadata[name].decode()
        except UnicodeDecodeError as e:
            # Mirrors handling done in pkg_resources.NullProvider.
            e.reason += f" in {name} file"
            raise

    def get_metadata_lines(self, name):
        # type: (str) -> Iterable[str]
        return yield_lines(self.get_metadata(name))

    def metadata_isdir(self, name):
        # type: (str) -> bool
        return False

    def metadata_listdir(self, name):
        # type: (str) -> List[str]
        return []

    def run_script(self, script_name, namespace):
        # type: (str, str) -> None
        pass
