My own Godot "custom.py" (useful default values and caching system for older versions)

custom.py

#!/usr/bin/env python
from misc.utility.scons_hints import *

import distutils
import os
import platform as platform_module

from SCons.Script import ARGUMENTS
from SCons.Variables.BoolVariable import TRUE_STRINGS


def has_command_line_tool(name):
    from shutil import which

    return which(name) is not None


def has_cache_tool_commit():
    from subprocess import run

    CACHE_TOOL_COMMIT = "0e4a4e3c4d602691ce1b4fc6a721c5c637ead57f"

    result = run(["git", "merge-base", "--is-ancestor", CACHE_TOOL_COMMIT, "HEAD"])
    return result.returncode == 0


def get_active_branch_name():
    from subprocess import run

    result = run(["git", "rev-parse", "--abbrev-ref", "HEAD"], capture_output=True, text=True)
    return result.stdout.strip()


if ARGUMENTS.get("custom", "yes") in TRUE_STRINGS:
    system = platform_module.system()
    compiledb = ARGUMENTS.get("compiledb", "yes")

    _current_platform = None
    if len(platform_module.mac_ver()[0]) > 0:
        _current_platform = "macos"
    elif system == "Linux" or system == "FreeBSD":
        _current_platform = "linux"
    elif len(platform_module.win32_ver()[0]) > 0:
        _current_platform = "windows"
    if _current_platform is not None:
        platform = ARGUMENTS.get("platform", _current_platform)

    dev_build = ARGUMENTS.get("dev_build", "yes")
    dev_mode = ARGUMENTS.get("dev_mode", "yes")
    scu_build = ARGUMENTS.get("scu_build", "yes")
    fast_unsafe = ARGUMENTS.get("fast_unsafe", "yes")
    target = ARGUMENTS.get("target", "editor")
    module_mono_enabled = ARGUMENTS.get("module_mono_enabled", "no")
    verbose = ARGUMENTS.get("verbose", "yes")
    # debug_symbols = ARGUMENTS.get("debug_symbols", "yes")
    # separate_debug_symbols = ARGUMENTS.get("separate_debug_symbols", "yes")

    if platform == "web":
        webgpu = ARGUMENTS.get("webgpu", "yes")
        if "DAWN_LIBS" in os.environ:
            dawn_libs = os.environ["DAWN_LIBS"]
        if "EMSCRIPTEN_INCLUDE_PATH" in os.environ:
            emscripten_include_path = os.environ["EMSCRIPTEN_INCLUDE_PATH"]

    if target == "template_debug" or target == "template_release":
        dev_mode = False
        optimize = ARGUMENTS.get("optimize", "size")
        if platform == "web":
            threads = ARGUMENTS.get("threads", "no")
            dev_build = ARGUMENTS.get("dev_build", "no")
    else:
        optimize = ARGUMENTS.get("optimize", "none")

    if platform == "linuxbsd":
        # Comment if you want to use clang instead of gcc
        use_llvm = ARGUMENTS.get("use_llvm", "yes")
        linker = ARGUMENTS.get("linker", "mold")
        pass
    elif platform == "macos":
        generate_bundle = ARGUMENTS.get("generate_bundle", "yes")
    elif platform == "windows":
        d3d12 = ARGUMENTS.get("d3d12", "yes")

    if has_command_line_tool("git"):
        _cache_dir_name = ".scons_cache"
        _active_branch_name = get_active_branch_name()
        if not (
            _active_branch_name == "master"
            and (_current_platform is None or _current_platform == platform)
            and target == "editor"
        ):
            _cache_dir_name = f".scons_cache__{_active_branch_name}__{platform}__{target}"

        _base_cache_path = os.path.join(os.getcwd(), ".scons_cache")
        _cache_path = os.path.join(os.getcwd(), _cache_dir_name)
        if (_base_cache_path != _cache_path) and (not os.path.isdir(_cache_path)) and (os.path.isdir(_base_cache_path)):
            distutils.dir_util.copy_tree(_base_cache_path, _cache_path)

        if has_cache_tool_commit():
            cache_path = ARGUMENTS.get("cache_path", _cache_dir_name)
            cache_limit = ARGUMENTS.get("cache_limit", 5)
        else:
            print(
                "INFO: This branch don't support `cache_path` and `cache_limit` parameters. Interfacing directly with SCons for cache."
            )
            if not os.getenv("SCONS_CACHE_LIMIT"):
                os.environ["SCONS_CACHE_LIMIT"] = "5120"
            if not os.getenv("SCONS_CACHE"):
                os.environ["SCONS_CACHE"] = _cache_path
    else:
        print("WARNING: Skipping caching. custom.py needs `git`.")

    # Variable clean-up.
    del _cache_dir_name
    del _active_branch_name
    del _base_cache_path
    del _cache_path

del distutils
del platform_module
del os

del ARGUMENTS
del TRUE_STRINGS