tuning x11-64 platform for aarch64 and pyhton3.9

README.rst

@@ -19,6 +19,10 @@ Godot Python, because you want Python on Godot !
 The goal of this project is to provide Python language support as a scripting
 module for the `Godot <http://godotengine.org>`_ game engine.
 
+Notes
+====
+
+This version is a hack to build godot-python on aarch64 (tested on RaspberryPi 4 2GB, swap maxxed out to 11+GB, Raspberry Pi OS / Debian 10.5), replacing platform x11-64. Before launching the build with the usual instructions below, grab manually an aarch64 build from `python-build-standalone project <https://github.com/indygreg/python-build-standalone/>`_ under the CI menu ("actions") -- aarch64 linux is not part of official releases and only comes with python3.9 as of 2021-05-30. Prefer a version without debug and optimisations, e.g. "lto". Place the .tar.zst package in ``/tmp/cpython-3.9.5-aarch64-unknown-linux-gnu.tar.zst``. Compilation will likely take hours.
 
 Quickstart
 ==========

platforms/x11-64/SConscript

@@ -19,25 +19,27 @@ else:
     env["godot_binary_download_platform"] = "x11.64"
 env["cpython_build"] = cpython_build
 env["cpython_build_dir"] = cpython_build
-env["DIST_SITE_PACKAGES"] = Dir(f"{env['DIST_PLATFORM']}/lib/python3.8/site-packages")
+env["DIST_SITE_PACKAGES"] = Dir(f"{env['DIST_PLATFORM']}/lib/python3.9/site-packages")
 
 
 ### Build config for pythonscript ###
 
 
-env.AppendUnique(CFLAGS=["-m64"])
-env.AppendUnique(LINKFLAGS=["-m64"])
+#env.AppendUnique(CFLAGS=["-m64"])
+#env.AppendUnique(LINKFLAGS=["-m64"])
 # Cannot use CPPPATH&LIBPATH here given headers are within `cpython_build` target,
 # so Scons consider the headers are a missing target
-env.AppendUnique(CFLAGS=[f"-I{cpython_build.abspath}/include/python3.8/"])
+env.AppendUnique(CFLAGS=[f"-I{cpython_build.abspath}/include/python3.9/"])
 env.AppendUnique(LINKFLAGS=[f"-L{cpython_build.abspath}/lib"])
 env.AppendUnique(CYTHON_COMPILE_DEPS=[cpython_build])
 
 
 ### Fetch Python prebuild ###
 
 
-CPYTHON_PREBUILD_URL = "https://github.com/indygreg/python-build-standalone/releases/download/20200822/cpython-3.8.5-x86_64-unknown-linux-gnu-pgo-20200823T0036.tar.zst"
+#CPYTHON_PREBUILD_URL = "https://github.com/indygreg/python-build-standalone/releases/download/20200822/cpython-3.8.5-x86_64-unknown-linux-gnu-pgo-20200823T0036.tar.zst"
+# download manually a binary for aarch64-unknown-linux-gnu and place it in /tmp/ E.g. grab a release or CI artifacts from https://github.com/indygreg/python-build-standalone -- prefer a version with optimisations and no debug, i.e. "lto"
+PYTHON_PREBUILD_URL = "file:///tmp/cpython-3.9.5-aarch64-unknown-linux-gnu.tar.zst"
 cpython_prebuild_archive = env.Download(
     target=File(CPYTHON_PREBUILD_URL.rsplit("/", 1)[1]), url=CPYTHON_PREBUILD_URL
 )
@@ -71,9 +73,9 @@ def generate_cpython_build(target, source, env):
     prebuild = Path(source[0].abspath) / "python"
 
     conf = json.loads((prebuild / "PYTHON.json").read_text())
-    assert conf["version"] == "5"
+    assert conf["version"] == "7"
     assert conf["libpython_link_mode"] == "shared"
-    assert conf["target_triple"] == "x86_64-unknown-linux-gnu"
+    assert conf["target_triple"] == "aarch64-unknown-linux-gnu"
 
     shutil.copytree(str(prebuild / "install"), str(build), symlinks=True)
     shutil.copytree(str(prebuild / "licenses"), str(build / "licenses"), symlinks=True)
@@ -87,7 +89,7 @@ def generate_cpython_build(target, source, env):
     assert config.exists()
     shutil.rmtree(str(config))
 
-    stdlib_path = build / "lib/python3.8"
+    stdlib_path = build / "lib/python3.9"
 
     # Remove tests lib (pretty big and basically useless)
     shutil.rmtree(str(stdlib_path / "test"))
@@ -101,12 +103,12 @@ def generate_cpython_build(target, source, env):
 
     # Zip the stdlib to save plenty of space \o/
     if env["compressed_stdlib"]:
-        tmp_stdlib_path = build / "lib/tmp_python3.8"
+        tmp_stdlib_path = build / "lib/tmp_python3.9"
         shutil.move(str(stdlib_path), str(tmp_stdlib_path))
         stdlib_path.mkdir()
         shutil.move(str(tmp_stdlib_path / "lib-dynload"), str(stdlib_path / "lib-dynload"))
         shutil.make_archive(
-            base_name=build / "lib/python38", format="zip", root_dir=str(tmp_stdlib_path)
+            base_name=build / "lib/python39", format="zip", root_dir=str(tmp_stdlib_path)
         )
         shutil.rmtree(str(tmp_stdlib_path))
         # Oddly enough, os.py must be present (even if empty !) otherwise

pythonscript/SConscript

@@ -14,7 +14,7 @@ elif env["platform"].startswith("osx"):
     c_env.AppendUnique(CFLAGS=["-Werror-implicit-function-declaration"])
 
 else:  # x11
-    c_env.AppendUnique(LIBS=["python3.8"])
+    c_env.AppendUnique(LIBS=["python3.9"])
     c_env.AppendUnique(LINKFLAGS=["-Wl,-rpath,'$$ORIGIN/lib'"])
     c_env.AppendUnique(CFLAGS=["-Werror-implicit-function-declaration"])
 c_env.Depends("pythonscript.c", env["cpython_build"])

requirements.txt

@@ -9,7 +9,7 @@ appdirs==1.4.4 \
     --hash=sha256:a841dacd6b99318a741b166adb07e19ee71a274450e68237b4650ca1055ab128
     # via black
 autopxd2==1.1.0 \
-    --hash=sha256:faa4b7eeb6b1d7217c46d3660640d4a72fb5c86d4559017c1f58a55d34332b2a
+    --hash=sha256:687d77b167020354c0e7d0d47b906494fb9004a74ca3c80a479c83d8cbe6eee1
     # via -r requirements.in
 black==20.8b1 \
     --hash=sha256:1c02557aa099101b9d21496f8a914e9ed2222ef70336404eeeac8edba836fbea

site_scons/site_tools/cython.py

@@ -98,7 +98,7 @@ def CythonCompile(env, target, source):
             SHLIBSUFFIX=".so",
             CFLAGS=cflags,
             LINKFLAGS=[*linkflags, *env["LINKFLAGS"]],
-            LIBS=["python3.8", "pythonscript"],
+            LIBS=["python3.9", "pythonscript"],
             # LIBS=[*env["CYTHON_LIBS"], *env["LIBS"]],
             # LIBPATH=[*env['CYTHON_LIBPATH'], *env['LIBPATH']]
         )