build: set the minimum macOS SDK to 10.15 (#47634)

* build: set the minumum macOS SDK to 10.15

* build: revert "Update mac_sdk_min to match minimum required SDK version"

This reverts commit 3d4654fc18.

.github/workflows/build.yml

@@ -184,7 +184,7 @@ jobs:
     with:
       target-platform: macos
       target-archs: x64 arm64
-      check-runs-on: macos-15
+      check-runs-on: macos-14
       gn-build-type: testing
     secrets: inherit
 
@@ -219,7 +219,7 @@ jobs:
     uses: ./.github/workflows/pipeline-electron-build-and-test.yml
     needs: checkout-macos
     with:
-      build-runs-on: macos-15-xlarge
+      build-runs-on: macos-14-xlarge
       test-runs-on: macos-13
       target-platform: macos
       target-arch: x64
@@ -237,7 +237,7 @@ jobs:
     uses: ./.github/workflows/pipeline-electron-build-and-test.yml
     needs: checkout-macos
     with:
-      build-runs-on: macos-15-xlarge
+      build-runs-on: macos-14-xlarge
       test-runs-on: macos-14
       target-platform: macos
       target-arch: arm64

.github/workflows/macos-publish.yml

@@ -47,7 +47,7 @@ jobs:
     needs: checkout-macos
     with:
       environment: production-release
-      build-runs-on: macos-15-xlarge
+      build-runs-on: macos-14-xlarge
       target-platform: macos
       target-arch: x64
       target-variant: darwin
@@ -62,7 +62,7 @@ jobs:
     needs: checkout-macos
     with:
       environment: production-release
-      build-runs-on: macos-15-xlarge
+      build-runs-on: macos-14-xlarge
       target-platform: macos
       target-arch: x64
       target-variant: mas
@@ -77,7 +77,7 @@ jobs:
     needs: checkout-macos
     with:
       environment: production-release
-      build-runs-on: macos-15-xlarge
+      build-runs-on: macos-14-xlarge
       target-platform: macos
       target-arch: arm64
       target-variant: darwin
@@ -92,7 +92,7 @@ jobs:
     needs: checkout-macos
     with:
       environment: production-release
-      build-runs-on: macos-15-xlarge
+      build-runs-on: macos-14-xlarge
       target-platform: macos
       target-arch: arm64
       target-variant: mas

patches/chromium/.patches

@@ -135,3 +135,4 @@ refactor_patch_electron_permissiontypes_into_blink.patch
 revert_views_remove_desktopwindowtreehostwin_window_enlargement.patch
 build_partial_revert_mac_fullscreen_top_chrome_mouse_events.patch
 revert_update_siso-chromium_image.patch
+build_set_mac_sdk_minimum_to_10.patch

patches/chromium/build_set_mac_sdk_minimum_to_10.patch

@@ -0,0 +1,26 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Keeley Hammond <khammond@slack-corp.com>
+Date: Tue, 1 Jul 2025 15:40:02 -0700
+Subject: build: Set MacOS SDK minimum back to 10
+
+This commit reverts 6493969: Update mac_sdk_min to
+match minimum required SDK version |
+https://chromium-review.googlesource.com/c/chromium/src/+/6493969
+
+This patch is purely to unblock nightlies while
+we merge an upstream fix and allocate additional space
+on the Mac runners. If this patch is still in main
+anytime after July 30, 2025, find @VerteDinde and yell
+at her.
+
+diff --git a/build/config/mac/mac_sdk_overrides.gni b/build/config/mac/mac_sdk_overrides.gni
+index 8f8ac1c218ce15fa5c1aecbbcd0b93281f6c52f2..15ddfd5cffbaba0704b3217e1ae4f2825f399d96 100644
+--- a/build/config/mac/mac_sdk_overrides.gni
++++ b/build/config/mac/mac_sdk_overrides.gni
+@@ -7,5 +7,5 @@
+ 
+ declare_args() {
+   # Minimum supported version of the Mac SDK.
+-  mac_sdk_min = "15"
++  mac_sdk_min = "10.15"
+ }