From 028ce9ecc954565ae196540d62a793200ade54b5 Mon Sep 17 00:00:00 2001
From: Tomas Grosup <tomasgrosup@microsoft.com>
Date: Mon, 17 Aug 2026 12:56:39 +0200
Subject: [PATCH 1/2] Unpin MSBuild deps and flow to VS 18.11
 (18.11.0-1.26417.9)

The Microsoft.Build.* deps were pinned at 18.10.0-1.26370.18 to keep them on
the net10.0 asset line while the product targeted net10.0. The product moved to
net11.0 (#20080) before the pin landed, so the pin's own unpin condition was
already met. In the VMR source-only build this pin causes prebuilts: the VMR
source-builds MSBuild on the 18.11.0 line (VS 18.11 channel), so an 18.10.0
reference cannot be satisfied in-tree and leaks to an external feed, dragging
its net10 System.* transitive closure with it.

Unpin the four Microsoft.Build.* deps and let the existing msbuild -> fsharp
VS 18.11 subscription flow the coherent build (darc update-dependencies), and
bump the CPM runtime floor 10.0.9 -> 10.0.10 since net11 MSBuild 18.11 pulls
System.Collections.Immutable / System.Reflection.Metadata / Security.Cryptography.Xml
at >= 10.0.10. VS 18.11 is the same channel the VMR (main and release/11.0.1xx)
consumes MSBuild from, restoring coherency and removing the prebuilts.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 3a3d99e1-5b05-409a-afd5-c8d9676360f4
---
 eng/Version.Details.props | 11 +++++------
 eng/Version.Details.xml   | 20 ++++++++------------
 eng/Versions.props        |  8 ++++----
 3 files changed, 17 insertions(+), 22 deletions(-)

diff --git a/eng/Version.Details.props b/eng/Version.Details.props
index 64c56630211..cf2da9e5711 100644
--- a/eng/Version.Details.props
+++ b/eng/Version.Details.props
@@ -7,12 +7,11 @@ This file should be imported by eng/Versions.props
   <PropertyGroup>
     <!-- dotnet-arcade dependencies -->
     <MicrosoftDotNetArcadeSdkPackageVersion>11.0.0-beta.26369.1</MicrosoftDotNetArcadeSdkPackageVersion>
-    <!-- dotnet-msbuild dependencies. Pinned at 18.10.0-1.26370.18 (see eng/Version.Details.xml):
-         later 18.10.0-1.26371.x builds dropped net10.0 assets and are incompatible with our net10.0 target. -->
-    <MicrosoftBuildPackageVersion>18.10.0-1.26370.18</MicrosoftBuildPackageVersion>
-    <MicrosoftBuildFrameworkPackageVersion>18.10.0-1.26370.18</MicrosoftBuildFrameworkPackageVersion>
-    <MicrosoftBuildTasksCorePackageVersion>18.10.0-1.26370.18</MicrosoftBuildTasksCorePackageVersion>
-    <MicrosoftBuildUtilitiesCorePackageVersion>18.10.0-1.26370.18</MicrosoftBuildUtilitiesCorePackageVersion>
+    <!-- dotnet-msbuild dependencies -->
+    <MicrosoftBuildPackageVersion>18.11.0-1.26417.9</MicrosoftBuildPackageVersion>
+    <MicrosoftBuildFrameworkPackageVersion>18.11.0-1.26417.9</MicrosoftBuildFrameworkPackageVersion>
+    <MicrosoftBuildTasksCorePackageVersion>18.11.0-1.26417.9</MicrosoftBuildTasksCorePackageVersion>
+    <MicrosoftBuildUtilitiesCorePackageVersion>18.11.0-1.26417.9</MicrosoftBuildUtilitiesCorePackageVersion>
     <!-- dotnet-optimization dependencies -->
     <optimizationlinuxarm64MIBCRuntimePackageVersion>1.0.0-prerelease.26407.1</optimizationlinuxarm64MIBCRuntimePackageVersion>
     <optimizationlinuxx64MIBCRuntimePackageVersion>1.0.0-prerelease.26407.1</optimizationlinuxx64MIBCRuntimePackageVersion>
diff --git a/eng/Version.Details.xml b/eng/Version.Details.xml
index 02c6cafa04f..82db3dfb115 100644
--- a/eng/Version.Details.xml
+++ b/eng/Version.Details.xml
@@ -2,25 +2,21 @@
 <Dependencies>
   <Source Uri="https://github.com/dotnet/dotnet" Mapping="fsharp" Sha="7cdb217445905f3342bbb0266a4497b9a014389a" BarId="326717" />
   <ProductDependencies>
-    <!-- Pinned at 18.10.0-1.26370.18: the 18.10.0-1.26371.x MSBuild builds dropped their net10.0
-         assets (they ship net11.0 + net472 only), which is incompatible with this repo's net10.0
-         product target framework - fsc/fsi fail to load Microsoft.Build.* at runtime. Unpin once
-         the product moves to net11.0 or MSBuild restores net10.0 assets. -->
-    <Dependency Name="Microsoft.Build" Version="18.10.0-1.26370.18" Pinned="true">
+    <Dependency Name="Microsoft.Build" Version="18.11.0-1.26417.9">
       <Uri>https://github.com/dotnet/msbuild</Uri>
-      <Sha>eae54023463db15e9a9081f35a959c9162797643</Sha>
+      <Sha>842fc358af70a4ef049ba4052dab78882af557ca</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.Build.Framework" Version="18.10.0-1.26370.18" Pinned="true">
+    <Dependency Name="Microsoft.Build.Framework" Version="18.11.0-1.26417.9">
       <Uri>https://github.com/dotnet/msbuild</Uri>
-      <Sha>eae54023463db15e9a9081f35a959c9162797643</Sha>
+      <Sha>842fc358af70a4ef049ba4052dab78882af557ca</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.Build.Tasks.Core" Version="18.10.0-1.26370.18" Pinned="true">
+    <Dependency Name="Microsoft.Build.Tasks.Core" Version="18.11.0-1.26417.9">
       <Uri>https://github.com/dotnet/msbuild</Uri>
-      <Sha>eae54023463db15e9a9081f35a959c9162797643</Sha>
+      <Sha>842fc358af70a4ef049ba4052dab78882af557ca</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.Build.Utilities.Core" Version="18.10.0-1.26370.18" Pinned="true">
+    <Dependency Name="Microsoft.Build.Utilities.Core" Version="18.11.0-1.26417.9">
       <Uri>https://github.com/dotnet/msbuild</Uri>
-      <Sha>eae54023463db15e9a9081f35a959c9162797643</Sha>
+      <Sha>842fc358af70a4ef049ba4052dab78882af557ca</Sha>
     </Dependency>
     <Dependency Name="Microsoft.CodeAnalysis" Version="5.10.0-1.26365.3">
       <Uri>https://github.com/dotnet/roslyn</Uri>
diff --git a/eng/Versions.props b/eng/Versions.props
index febf548022a..03905c8726c 100644
--- a/eng/Versions.props
+++ b/eng/Versions.props
@@ -89,13 +89,13 @@
     <SystemMemoryVersion>4.6.3</SystemMemoryVersion>
     <SystemRuntimeCompilerServicesUnsafeVersion>6.1.2</SystemRuntimeCompilerServicesUnsafeVersion>
     <!-- System.* packages from dotnet/runtime flow via Version.Details.xml / Version.Details.props (darc). -->
-    <!-- fsc/fsi and FSharp.Build.UnitTests consume MSBuild 18.10, which pulls these dotnet/runtime packages
-         transitively at >= 10.0.9 — in product/PR builds AND in source-build (which builds live MSBuild 18.10
+    <!-- fsc/fsi and FSharp.Build.UnitTests consume MSBuild 18.11, which pulls these dotnet/runtime packages
+         transitively at >= 10.0.10 — in product/PR builds AND in source-build (which builds live MSBuild 18.11
          too, hence the floor must apply there as well). CPM transitive pinning needs the *central* pin to meet
          that floor, so define dedicated ...CentralVersion properties for eng/Packages.props. These do NOT touch
          the darc-flowed $(System*Version) properties, which stay authoritative for FSharp.Compiler.Service's
          shipped nuspec dependency metadata (FCS does not pull MSBuild, so it keeps the darc version). The floor
-         only raises when darc is below it; once darc flows >= 10.0.9 the darc version wins, so this never
+         only raises when darc is below it; once darc flows >= 10.0.10 the darc version wins, so this never
          freezes or downgrades the flow. -->
     <SystemSecurityCryptographyXmlCentralVersion>$(SystemSecurityCryptographyXmlVersion)</SystemSecurityCryptographyXmlCentralVersion>
     <SystemCollectionsImmutableCentralVersion>$(SystemCollectionsImmutableVersion)</SystemCollectionsImmutableCentralVersion>
@@ -104,7 +104,7 @@
 
   <PropertyGroup>
     <!-- Minimum central version the MSBuild-pulled dotnet/runtime packages must meet (see comment above). -->
-    <SystemRuntimeCentralFloorVersion>10.0.9</SystemRuntimeCentralFloorVersion>
+    <SystemRuntimeCentralFloorVersion>10.0.10</SystemRuntimeCentralFloorVersion>
     <SystemSecurityCryptographyXmlCentralVersion Condition="$([MSBuild]::VersionLessThan('$(SystemSecurityCryptographyXmlVersion)', '$(SystemRuntimeCentralFloorVersion)'))">$(SystemRuntimeCentralFloorVersion)</SystemSecurityCryptographyXmlCentralVersion>
     <SystemCollectionsImmutableCentralVersion Condition="$([MSBuild]::VersionLessThan('$(SystemCollectionsImmutableVersion)', '$(SystemRuntimeCentralFloorVersion)'))">$(SystemRuntimeCentralFloorVersion)</SystemCollectionsImmutableCentralVersion>
     <SystemReflectionMetadataCentralVersion Condition="$([MSBuild]::VersionLessThan('$(SystemReflectionMetadataVersion)', '$(SystemRuntimeCentralFloorVersion)'))">$(SystemRuntimeCentralFloorVersion)</SystemReflectionMetadataCentralVersion>

From cc0cbcbfe4ebdff60de1f49a0e83e624d90e65b8 Mon Sep 17 00:00:00 2001
From: Tomas Grosup <tomasgrosup@microsoft.com>
Date: Tue, 18 Aug 2026 11:05:25 +0200
Subject: [PATCH 2/2] Build EndToEndBuildTests with -ci to avoid flaky
 UpdateXlf failure

The EndToEndBuildTests job ran .\Build.cmd -c Release -pack without -ci, so
Arcade treated it as a dev build and defaulted UpdateXlfOnBuild=true. That runs
the XliffTasks UpdateXlf target after each inner-TFM build of the multi-targeted
FSharp.Core, which intermittently fails with 'MSB4057: The target "UpdateXlf"
does not exist' when the XliffTasks import has not been applied for that inner
build yet. The same flake hits main (e.g. build 1555456). Adding -ci keeps
UpdateXlfOnBuild off, matching every other build job in this pipeline (including
the -ci -pack AheadOfTime job).

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 3a3d99e1-5b05-409a-afd5-c8d9676360f4
---
 azure-pipelines-PR.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/azure-pipelines-PR.yml b/azure-pipelines-PR.yml
index ae2ceb05d6c..bac84adeb5b 100644
--- a/azure-pipelines-PR.yml
+++ b/azure-pipelines-PR.yml
@@ -559,7 +559,7 @@ stages:
           steps:
           - checkout: self
             clean: true
-          - script: .\Build.cmd -c Release -pack
+          - script: .\Build.cmd -ci -c Release -pack
             env:
               NativeToolsOnMachine: true
           - script: .\eng\common\dotnet.cmd fsi .\tests\AheadOfTime\NetPackage\VerifyNetPackage.fsx -- .\artifacts\packages\Release