From 3557826c6021371572344eeee50a78f568f9ec80 Mon Sep 17 00:00:00 2001
From: Eric Salituro <esalituro@icloud.com>
Date: Wed, 8 Apr 2026 15:17:23 -0700
Subject: [PATCH 1/2] fix(builder): pin docker-bake to linux/amd64 on macOS

Docker Desktop on Apple Silicon defaults to linux/arm64; set bake platforms
so local builds match CI (linux/amd64).

- Apply black formatting to builder.
- Tests: mock sys.platform for platform key and full bake dict equality on macOS.

Signed-off-by: Eric Salituro <esalituro@icloud.com>
Made-with: Cursor
---
 python/aswfdocker/builder.py            | 11 +++++--
 python/aswfdocker/tests/test_builder.py | 40 +++++++++++++++++++++++++
 2 files changed, 48 insertions(+), 3 deletions(-)

diff --git a/python/aswfdocker/builder.py b/python/aswfdocker/builder.py
index 5445064e..f05ff458 100644
--- a/python/aswfdocker/builder.py
+++ b/python/aswfdocker/builder.py
@@ -3,10 +3,12 @@
 """
 CI Image and Package Builder
 """
+
 import logging
 import subprocess
 import json
 import os
+import sys
 import tempfile
 import typing
 
@@ -109,9 +111,9 @@ def make_bake_dict(
                             + "_VERSION"
                         ),
                         "ASWF_CONAN_HOME": constants.ASWF_CONAN_HOME,
-                        "ASWF_CONAN_BUILD_MISSING": "--build=missing"
-                        if build_missing
-                        else "",
+                        "ASWF_CONAN_BUILD_MISSING": (
+                            "--build=missing" if build_missing else ""
+                        ),
                         "ASWF_CONAN_NO_REMOTE": "--no-remote" if no_remote else "",
                         "ASWF_CONAN_PUSH": "TRUE" if self.push else "",
                     }
@@ -132,6 +134,9 @@ def make_bake_dict(
                     "id=conan_password,env=CONAN_PASSWORD",
                 ],
             }
+            # Docker Desktop on Apple Silicon defaults to linux/arm64; pin amd64 to match CI.
+            if sys.platform == "darwin":
+                target_dict["platforms"] = ["linux/amd64"]
             if self.group_info.type == constants.ImageType.PACKAGE:
                 if not use_conan:
                     target_dict["target"] = image
diff --git a/python/aswfdocker/tests/test_builder.py b/python/aswfdocker/tests/test_builder.py
index 962d7688..7a75a107 100644
--- a/python/aswfdocker/tests/test_builder.py
+++ b/python/aswfdocker/tests/test_builder.py
@@ -8,6 +8,7 @@
 import unittest
 import logging
 import tempfile
+from unittest.mock import patch
 
 from click.testing import CliRunner
 
@@ -22,6 +23,43 @@ def setUp(self):
             repo_uri="notauri", source_branch="testing", aswf_version="2024.123"
         )
 
+    @patch.object(builder.sys, "platform", "darwin")
+    def test_bake_dict_sets_linux_amd64_platform_on_macos(self):
+        """Match CI arch on Docker Desktop (Apple Silicon defaults to linux/arm64)."""
+        b = builder.Builder(
+            self.build_info,
+            groupinfo.GroupInfo(
+                names=["base"],
+                versions=["2019"],
+                type_=constants.ImageType.IMAGE,
+                targets=[],
+            ),
+        )
+        baked = b.make_bake_dict(False, False)
+        self.assertEqual(
+            baked["target"]["ci-base-2019"]["platforms"],
+            ["linux/amd64"],
+        )
+
+    def test_bake_dict_omits_platforms_when_not_darwin(self):
+        b = builder.Builder(
+            self.build_info,
+            groupinfo.GroupInfo(
+                names=["base"],
+                versions=["2019"],
+                type_=constants.ImageType.IMAGE,
+                targets=[],
+            ),
+        )
+        for plat in ("linux", "win32"):
+            with patch.object(builder.sys, "platform", plat):
+                baked = b.make_bake_dict(False, False)
+            self.assertNotIn(
+                "platforms",
+                baked["target"]["ci-base-2019"],
+                msg=f"host sys.platform={plat!r}",
+            )
+
     def test_package_otio_2024_dict(self):
         b = builder.Builder(
             self.build_info,
@@ -115,6 +153,7 @@ def test_image_base_2019_dict(self):
             baked["target"]["ci-base-2019"]["args"]["ASWF_VERSION"], base_version
         )
 
+    @patch.object(builder.sys, "platform", "linux")
     def test_image_base_2019clang_dict(self):
         b = builder.Builder(
             self.build_info,
@@ -207,6 +246,7 @@ def test_image_base_2019clang_dict(self):
             },
         )
 
+    @patch.object(builder.sys, "platform", "linux")
     def test_image_base_2019_2020_dict(self):
         b = builder.Builder(
             self.build_info,

From aa572609e51414fc804be0a72fe3ef4eeacf97cb Mon Sep 17 00:00:00 2001
From: Eric Salituro <esalituro@icloud.com>
Date: Wed, 8 Apr 2026 15:37:21 -0700
Subject: [PATCH 2/2] docs: macOS build notes

- README: Linux artifacts on macOS, Docker 8c/16GB, buildx on Docker VMM vs Rosetta

Signed-off-by: Eric Salituro <esalituro@icloud.com>
Made-with: Cursor
---
 README.md | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/README.md b/README.md
index 1d7b9103..e7c8bb4b 100644
--- a/README.md
+++ b/README.md
@@ -254,6 +254,17 @@ aswfdocker --verbose build --ci-image-type IMAGE --group vfx1 --version 2026 --t
 aswfdocker build --ci-image-type aswftesting/ci-openexr:2026
 ```
 
+### Building on macOS
+
+Native macOS support is our goal, but due to limited resources, active development is intermittent. In the meantime, our existing build workflows only build Linux artifacts on macOS: `aswfdocker` drives Linux containers (for example `linux/amd64` images and Conan packages for Linux), not native macOS toolchains.
+
+Configure Docker with a minimum of:
+
+- 8 CPU cores allocated to Docker
+- 16 GB of memory allocated to Docker
+
+Due to conflicts with Rosetta, [buildx](https://docs.docker.com/buildx/working-with-buildx/) should be run on the Docker VMM.
+
 ## Use Cases
 
 ### GitHub Actions