Method build_with_merged_bin

ci/compiler/pio.py:1401–1635

Build example and generate merged binary. Args: example: Example name to build output_path: Optional custom output path for merged binary Returns: SketchResult with merged_bin_path populated

(
        self, example: str, output_path: Optional[Path] = None
    )

        return merged_bin if merged_bin.exists() else None

    def build_with_merged_bin(
        self, example: str, output_path: Optional[Path] = None
    ) -> SketchResult:
        """Build example and generate merged binary.

        Args:
            example: Example name to build
            output_path: Optional custom output path for merged binary

        Returns:
            SketchResult with merged_bin_path populated
        """
        # 1. Validate board support
        if not self.supports_merged_bin():
            return SketchResult(
                success=False,
                output=f"Board {self.board.board_name} does not support merged binary. "
                f"Supported platforms: ESP32, ESP8266",
                build_dir=self.build_dir,
                example=example,
            )

        # 2. Build normally first.
        #
        # Both backends produce the artifact set ``esptool merge_bin`` needs
        # (``firmware.bin`` + ``bootloader.bin`` + ``partitions.bin``), just
        # in different directories. ``_artifacts_dir`` returns whichever path
        # the active backend wrote to, so the merge step below reads from
        # the right place without copying anything around.
        #
        # fbuild >= 2.1.7 is required for ESP32 merged-bin support — earlier
        # versions did not emit the boot/partition artifacts (FastLED#2287).
        cancelled = threading.Event()
        result = self._internal_build_no_lock(example, cancelled)
        if not result.success:
            return result

        # 3. Use esptool to merge binaries
        # PlatformIO doesn't have a merge_bin target - we must use esptool directly
        env_name = self.board.board_name
        artifacts_dir = self._artifacts_dir(env_name)

        # Find required binary components
        bootloader_bin = artifacts_dir / "bootloader.bin"
        partitions_bin = artifacts_dir / "partitions.bin"
        boot_app0_bin = artifacts_dir / "boot_app0.bin"
        firmware_bin = artifacts_dir / "firmware.bin"

        # Verify all required files exist
        missing_files: list[str] = []
        for bin_file in [bootloader_bin, partitions_bin, firmware_bin]:
            if not bin_file.exists():
                missing_files.append(str(bin_file))

        if missing_files:
            # The build appeared to succeed but the expected artifacts aren't
            # where we look for them. Most often this means the compile
            # actually failed earlier, or fbuild's ESP32 orchestrator skipped