From 7b931c0a7748a1d5b5d647cf8ef2404aa1520730 Mon Sep 17 00:00:00 2001
From: Jeremy Koritzinsky <jekoritz@microsoft.com>
Date: Mon, 9 Mar 2020 10:38:44 -0700
Subject: [PATCH 1/2] Disable IBCMerge on mac across the board.

---
 eng/codeOptimization.targets | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/eng/codeOptimization.targets b/eng/codeOptimization.targets
index 9f135452346a24..bf143e171e3b5e 100644
--- a/eng/codeOptimization.targets
+++ b/eng/codeOptimization.targets
@@ -4,6 +4,10 @@
      <IsEligibleForNgenOptimization>true</IsEligibleForNgenOptimization>
      <IsEligibleForNgenOptimization Condition="'$(IsReferenceAssembly)' == 'true'">false</IsEligibleForNgenOptimization>
      <IsEligibleForNgenOptimization Condition="'$(GeneratePlatformNotSupportedAssembly)' == 'true' or '$(GeneratePlatformNotSupportedAssemblyMessage)' != ''">false</IsEligibleForNgenOptimization>
+      <!-- There's an issue causing IBCMerge failures across many of our assemblies on Mac, so disable
+           IBCMerge optimizations on Mac for now to unblock the offical build.
+      -->
+      <IsEligibleForNgenOptimization Condition="'$(TargetOS)' == 'OSX'">false</IsEligibleForNgenOptimization>
   </PropertyGroup>
 
   <Target Name="SetApplyNgenOptimization"

From 96c53add720ea197f949246c8c5056b00897f4c6 Mon Sep 17 00:00:00 2001
From: Jeremy Koritzinsky <jekoritz@microsoft.com>
Date: Mon, 9 Mar 2020 11:45:00 -0700
Subject: [PATCH 2/2] Update comment to include link to issue.

---
 eng/codeOptimization.targets | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/eng/codeOptimization.targets b/eng/codeOptimization.targets
index bf143e171e3b5e..cbd2474984592a 100644
--- a/eng/codeOptimization.targets
+++ b/eng/codeOptimization.targets
@@ -4,8 +4,10 @@
      <IsEligibleForNgenOptimization>true</IsEligibleForNgenOptimization>
      <IsEligibleForNgenOptimization Condition="'$(IsReferenceAssembly)' == 'true'">false</IsEligibleForNgenOptimization>
      <IsEligibleForNgenOptimization Condition="'$(GeneratePlatformNotSupportedAssembly)' == 'true' or '$(GeneratePlatformNotSupportedAssemblyMessage)' != ''">false</IsEligibleForNgenOptimization>
-      <!-- There's an issue causing IBCMerge failures across many of our assemblies on Mac, so disable
+      <!-- There's an issue causing IBCMerge failures because of mismatched MVIDs
+           across many of our assemblies on Mac, so disable
            IBCMerge optimizations on Mac for now to unblock the offical build.
+           See issue https://github.com/dotnet/runtime/issues/33303
       -->
       <IsEligibleForNgenOptimization Condition="'$(TargetOS)' == 'OSX'">false</IsEligibleForNgenOptimization>
   </PropertyGroup>