feat: if failed (retry)

Signed-off-by: Henry Schreiner <[email protected]>

docs/overrides.md

@@ -132,6 +132,19 @@ SDist.
 This will be true if the `PKG-INFO` file exists, that is, if this is coming
 from an SDist. Takes a bool.
 
+### `failed` (bool)
+
+This override is a bit special. If a build fails, scikit-build-core will check
+to see if there'a a matching `failed = true` override. If there is, the the build will
+be retried once with the new settings. This can be used to build a pure-Python fallback
+if a build fails, for example:
+
+```toml
+[[tool.scikit-build.overrides]]
+if.failed = true
+wheel.cmake = false
+```
+
 ## Any matching condition
 
 If you use `if.any` instead of `if`, then the override is true if any one of the

src/scikit_build_core/build/_init.py

@@ -15,9 +15,9 @@ def __dir__() -> list[str]:
 @functools.lru_cache(1)
 def setup_logging(log_level: str) -> None:
     level_value = LEVEL_VALUE[log_level]
+    logger.setLevel(level_value)
 
     ch = logging.StreamHandler()
-    ch.setLevel(level_value)
     # create formatter and add it to the handlers
     formatter = logging.Formatter(
         "%(asctime)s - %(name)s - %(levelname)s - %(message)s"

src/scikit_build_core/build/wheel.py

@@ -7,19 +7,20 @@
 import sysconfig
 import tempfile
 from pathlib import Path
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Any
 
 from packaging.requirements import Requirement
 from packaging.utils import canonicalize_name
 
 from .. import __version__
 from .._compat import tomllib
 from .._compat.typing import Literal, assert_never
-from .._logging import logger, rich_print
+from .._logging import LEVEL_VALUE, logger, rich_print
 from .._shutil import fix_win_37_all_permissions
 from ..builder.builder import Builder, archs_to_tags, get_archs
 from ..builder.wheel_tag import WheelTag
 from ..cmake import CMake, CMaker
+from ..errors import FailedLiveProcessError
 from ..settings.skbuild_read_settings import SettingsReader
 from ._editable import editable_redirect, libdir_to_installed, mapping_to_modules
 from ._init import setup_logging
@@ -123,6 +124,7 @@ def _build_wheel_impl(
 ) -> WheelImplReturn:
     """
     Build a wheel or just prepare metadata (if wheel dir is None). Can be editable.
+    Handles one retry attempt if "failed" override present.
     """
     state: Literal["sdist", "wheel", "editable", "metadata_wheel", "metadata_editable"]
     if exit_after_config:
@@ -136,9 +138,10 @@ def _build_wheel_impl(
     with pyproject_path.open("rb") as ft:
         pyproject = tomllib.load(ft)
 
-    settings_reader = SettingsReader(pyproject, config_settings or {}, state=state)
-    settings = settings_reader.settings
-    setup_logging(settings.logging.level)
+    settings_reader = SettingsReader(
+        pyproject, config_settings or {}, state=state, retry=False
+    )
+    setup_logging(settings_reader.settings.logging.level)
 
     settings_reader.validate_may_exit()
 
@@ -156,6 +159,56 @@ def _build_wheel_impl(
             "ninja should not be in build-system.requires - scikit-build-core will inject it as needed"
         )
 
+    try:
+        return _build_wheel_impl_impl(
+            wheel_directory,
+            metadata_directory,
+            exit_after_config=exit_after_config,
+            editable=editable,
+            state=state,
+            settings=settings_reader.settings,
+            pyproject=pyproject,
+        )
+    except FailedLiveProcessError as err:
+        settings_reader = SettingsReader(
+            pyproject, config_settings or {}, state=state, retry=True
+        )
+        if "failed" not in settings_reader.overrides:
+            raise
+
+        rich_print(
+            f"\n[yellow bold]*** {' '.join(err.args)} - retrying due to override..."
+        )
+
+        logger.setLevel(LEVEL_VALUE[settings_reader.settings.logging.level])
+
+        settings_reader.validate_may_exit()
+
+        return _build_wheel_impl_impl(
+            wheel_directory,
+            metadata_directory,
+            exit_after_config=exit_after_config,
+            editable=editable,
+            state=state,
+            settings=settings_reader.settings,
+            pyproject=pyproject,
+        )
+
+
+def _build_wheel_impl_impl(
+    wheel_directory: str | None,
+    metadata_directory: str | None,
+    *,
+    exit_after_config: bool = False,
+    editable: bool,
+    state: Literal["sdist", "wheel", "editable", "metadata_wheel", "metadata_editable"],
+    settings: ScikitBuildSettings,
+    pyproject: dict[str, Any],
+) -> WheelImplReturn:
+    """
+    Build a wheel or just prepare metadata (if wheel dir is None). Can be editable.
+    """
+
     metadata = get_standard_metadata(pyproject, settings)
 
     if metadata.version is None:

src/scikit_build_core/resources/scikit-build.schema.json

@@ -628,6 +628,10 @@
           "type": "boolean",
           "description": "Whether the build is from an sdist."
         },
+        "failed": {
+          "type": "boolean",
+          "description": "Matches if the build fails. A build will be retried if there is at least one matching override with this set to true."
+        },
         "env": {
           "type": "object",
           "patternProperties": {

src/scikit_build_core/settings/skbuild_read_settings.py

@@ -72,6 +72,7 @@ def override_match(
         "sdist", "wheel", "editable", "metadata_wheel", "metadata_editable"
     ],
     has_dist_info: bool,
+    retry: bool,
     python_version: str | None = None,
     implementation_name: str | None = None,
     implementation_version: str | None = None,
@@ -81,25 +82,35 @@ def override_match(
     env: dict[str, str] | None = None,
     state: str | None = None,
     from_sdist: bool | None = None,
-) -> bool:
+    failed: bool | None = None,
+) -> set[str]:
+    """
+    Check if the current environment matches the overrides. Returns the set of matched keys.
+    """
     # This makes a matches list. A match is a string; if it's an empty string,
     # then it did not match. If it's not empty, it did match, and the string
     # will be printed in the logs - it's the match reason. If match_all is True,
     # then all must match, otherwise any match will count.
     matches = []
 
+    passed_keys = set()
+
     if current_env is None:
         current_env = os.environ
 
     if python_version is not None:
         current_python_version = ".".join(str(x) for x in sys.version_info[:2])
         match_msg = version_match(current_python_version, python_version, "Python")
         matches.append(match_msg)
+        if match_msg:
+            passed_keys.add("python-version")
 
     if implementation_name is not None:
         current_impementation_name = sys.implementation.name
         match_msg = regex_match(current_impementation_name, implementation_name)
         matches.append(match_msg)
+        if match_msg:
+            passed_keys.add("implementation-name")
 
     if implementation_version is not None:
         info = sys.implementation.version
@@ -111,25 +122,45 @@ def override_match(
             version, implementation_version, "Python implementation"
         )
         matches.append(match_msg)
+        if match_msg:
+            passed_keys.add("implementation-version")
 
     if platform_system is not None:
         current_platform_system = sys.platform
         match_msg = regex_match(current_platform_system, platform_system)
         matches.append(match_msg)
+        if match_msg:
+            passed_keys.add("platform-system")
 
     if platform_machine is not None:
         current_platform_machine = platform.machine()
         match_msg = regex_match(current_platform_machine, platform_machine)
         matches.append(match_msg)
+        if match_msg:
+            passed_keys.add("platform-machine")
 
     if platform_node is not None:
         current_platform_node = platform.node()
         match_msg = regex_match(current_platform_node, platform_node)
         matches.append(match_msg)
+        if match_msg:
+            passed_keys.add("platform-node")
 
     if state is not None:
         match_msg = regex_match(current_state, state)
         matches.append(match_msg)
+        if match_msg:
+            passed_keys.add("state")
+
+    if failed is not None:
+        if failed and retry:
+            matches.append("Previous run failed")
+            passed_keys.add("failed")
+        elif not failed and not retry:
+            matches.append("Running on a fresh run")
+            passed_keys.add("failed")
+        else:
+            matches.append("")
 
     if from_sdist is not None:
         if has_dist_info:
@@ -140,17 +171,21 @@ def override_match(
     if env:
         for key, value in env.items():
             if isinstance(value, bool):
-                matches.append(
+                match_msg = (
                     f"env {key} is {value}"
                     if strtobool(current_env.get(key, "")) == value
                     else ""
                 )
+                matches.append(match_msg)
+                passed_keys.add(f"env.{key}")
             elif key not in current_env:
                 matches.append("")
             else:
                 current_value = current_env.get(key, "")
                 match_msg = regex_match(current_value, value)
                 matches.append(match_msg and f"env {key}: {match_msg}")
+                if match_msg:
+                    passed_keys.add(f"env.{key}")
 
     if not matches:
         msg = "At least one override must be provided"
@@ -164,7 +199,8 @@ def override_match(
         matched = any(matches)
         if matched:
             logger.info("Overrides {}", " or ".join([m for m in matches if m]))
-    return matched
+
+    return passed_keys if matched else set()
 
 
 def _handle_minimum_version(
@@ -273,17 +309,20 @@ def inherit_join(
 
 def process_overides(
     tool_skb: dict[str, Any],
+    *,
     state: Literal["sdist", "wheel", "editable", "metadata_wheel", "metadata_editable"],
+    retry: bool,
     env: Mapping[str, str] | None = None,
-) -> None:
+) -> set[str]:
     """
     Process overrides into the main dictionary if they match. Modifies the input
     dictionary. Must be run from the package directory.
     """
     has_dist_info = Path("PKG-INFO").is_file()
 
+    global_matched: set[str] = set()
     for override in tool_skb.pop("overrides", []):
-        matched = True
+        matched: set[str] | None = None
         if_override = override.pop("if", None)
         if not if_override:
             msg = "At least one 'if' override must be provided"
@@ -299,6 +338,7 @@ def process_overides(
                 current_env=env,
                 current_state=state,
                 has_dist_info=has_dist_info,
+                retry=retry,
                 **select,
             )
 
@@ -309,13 +349,23 @@ def process_overides(
 
         select = {k.replace("-", "_"): v for k, v in if_override.items()}
         if select:
-            matched = matched and override_match(
+            each_matched = override_match(
                 match_all=True,
                 current_env=env,
                 current_state=state,
                 has_dist_info=has_dist_info,
+                retry=retry,
                 **select,
             )
+            if matched is None:
+                matched = each_matched
+            elif matched and each_matched:
+                matched |= each_matched
+            else:
+                matched = set()
+        if matched is None:
+            matched = set()
+        global_matched |= matched
         if matched:
             for key, value in override.items():
                 inherit1 = inherit_override.get(key, {})
@@ -334,6 +384,7 @@ def process_overides(
                     tool_skb[key] = inherit_join(
                         value, tool_skb.get(key), inherit_override_tmp
                     )
+    return global_matched
 
 
 class SettingsReader:
@@ -348,12 +399,18 @@ def __init__(
         extra_settings: Mapping[str, Any] | None = None,
         verify_conf: bool = True,
         env: Mapping[str, str] | None = None,
+        retry: bool = False,
     ) -> None:
         self.state = state
 
         # Handle overrides
         pyproject = copy.deepcopy(pyproject)
-        process_overides(pyproject.get("tool", {}).get("scikit-build", {}), state, env)
+        self.overrides = process_overides(
+            pyproject.get("tool", {}).get("scikit-build", {}),
+            state=state,
+            env=env,
+            retry=retry,
+        )
 
         # Support for minimum-version='build-system.requires'
         tmp_min_v = (
@@ -385,7 +442,7 @@ def __init__(
 
         if extra_settings is not None:
             extra_skb = copy.deepcopy(dict(extra_settings))
-            process_overides(extra_skb, state, env)
+            process_overides(extra_skb, state=state, env=env, retry=retry)
             toml_srcs.insert(0, TOMLSource(settings=extra_skb))
 
         prefixed = {

src/scikit_build_core/settings/skbuild_schema.py

@@ -120,6 +120,10 @@ def generate_skbuild_schema(tool_name: str = "scikit-build") -> dict[str, Any]:
                 "type": "boolean",
                 "description": "Whether the build is from an sdist.",
             },
+            "failed": {
+                "type": "boolean",
+                "description": "Matches if the build fails. A build will be retried if there is at least one matching override with this set to true.",
+            },
             "env": {
                 "type": "object",
                 "patternProperties": {

tests/conftest.py

@@ -302,6 +302,15 @@ def navigate_editable(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> Packag
     return package
 
 
+@pytest.fixture()
+def broken_fallback(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> PackageInfo:
+    package = PackageInfo(
+        "broken_fallback",
+    )
+    process_package(package, tmp_path, monkeypatch)
+    return package
+
+
 @pytest.fixture()
 def package_sdist_config(
     tmp_path: Path, monkeypatch: pytest.MonkeyPatch