From b48d052f64a13ca07552aeed2a9bd85bb8594218 Mon Sep 17 00:00:00 2001
From: Alex Hoppen <ahoppen@apple.com>
Date: Wed, 13 Aug 2025 13:06:32 +0200
Subject: [PATCH 1/2] Revert "[Windows] Use a multiroot data file to test
 (corelibs-)foundation on Windows"

This reverts commit 61f833c04c6ef9521b59d9ba7749cb1d862c0ed2.
---
 utils/build.ps1                                   | 15 ++++-----------
 .../contents.xcworkspacedata                      |  3 ---
 2 files changed, 4 insertions(+), 14 deletions(-)

diff --git a/utils/build.ps1 b/utils/build.ps1
index 792976cc8f6ad..ab290d4f59484 100644
--- a/utils/build.ps1
+++ b/utils/build.ps1
@@ -2834,17 +2834,12 @@ function Build-Foundation {
 }
 
 function Test-Foundation {
-  $ScratchPath = "$BinaryCache\$($BuildPlatform.Triple)\FoundationTests"
-
   # Foundation tests build via swiftpm rather than CMake
   Build-SPMProject `
     -Action Test `
     -Src $SourceCache\swift-foundation `
-    -Bin "$ScratchPath" `
-    -Platform $BuildPlatform `
-    -Configuration $FoundationTestConfiguration `
-    --multiroot-data-file "$SourceCache\swift\utils\build_swift\resources\SwiftPM-Unified-Build.xcworkspace" `
-    --test-product swift-foundationPackageTests
+    -Bin "$BinaryCache\$($BuildPlatform.Triple)\CoreFoundationTests" `
+    -Platform $BuildPlatform
 
   Invoke-IsolatingEnvVars {
     $env:DISPATCH_INCLUDE_PATH="$(Get-SwiftSDK $BuildPlatform.OS)/usr/include"
@@ -2856,12 +2851,10 @@ function Test-Foundation {
     Build-SPMProject `
       -Action Test `
       -Src $SourceCache\swift-corelibs-foundation `
-      -Bin "$ScratchPath" `
+      -Bin "$BinaryCache\$($BuildPlatform.Triple)\FoundationTests" `
       -Platform $BuildPlatform `
       -Configuration $FoundationTestConfiguration `
-      --multiroot-data-file "$SourceCache\swift\utils\build_swift\resources\SwiftPM-Unified-Build.xcworkspace" `
-      --test-product swift-corelibs-foundationPackageTests `
-      -j 1 # Running parallel causes a non-deterministic crash in CI only, see https://github.com/swiftlang/swift/issues/83606
+      -j 1
   }
 }
 
diff --git a/utils/build_swift/resources/SwiftPM-Unified-Build.xcworkspace/contents.xcworkspacedata b/utils/build_swift/resources/SwiftPM-Unified-Build.xcworkspace/contents.xcworkspacedata
index 605ae4dc932d6..98690cb842e09 100644
--- a/utils/build_swift/resources/SwiftPM-Unified-Build.xcworkspace/contents.xcworkspacedata
+++ b/utils/build_swift/resources/SwiftPM-Unified-Build.xcworkspace/contents.xcworkspacedata
@@ -6,13 +6,10 @@
    <FileRef location = "group:../../../../sourcekit-lsp"></FileRef>
    <FileRef location = "group:../../../../swift-argument-parser"></FileRef>
    <FileRef location = "group:../../../../swift-collections"></FileRef>
-   <FileRef location = "group:../../../../swift-corelibs-foundation"></FileRef>
    <FileRef location = "group:../../../../swift-crypto"></FileRef>
    <FileRef location = "group:../../../../swift-docc"></FileRef>
    <FileRef location = "group:../../../../swift-driver"></FileRef>
    <FileRef location = "group:../../../../swift-format"></FileRef>
-   <FileRef location = "group:../../../../swift-foundation"></FileRef>
-   <FileRef location = "group:../../../../swift-foundation-icu"></FileRef>
    <FileRef location = "group:../../../../swift-stress-tester/SourceKitStressTester"></FileRef>
    <FileRef location = "group:../../../../swift-syntax"></FileRef>
    <FileRef location = "group:../../../../swift-syntax/CodeGeneration"></FileRef>

From 8ef0e2ae92fe792ff41b30c51a3f8228ede717b0 Mon Sep 17 00:00:00 2001
From: Alex Hoppen <ahoppen@apple.com>
Date: Wed, 13 Aug 2025 13:08:00 +0200
Subject: [PATCH 2/2] Add comment to `-j 1` for Foundation test execution

---
 utils/build.ps1 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/utils/build.ps1 b/utils/build.ps1
index ab290d4f59484..ce7b673a598ad 100644
--- a/utils/build.ps1
+++ b/utils/build.ps1
@@ -2854,7 +2854,7 @@ function Test-Foundation {
       -Bin "$BinaryCache\$($BuildPlatform.Triple)\FoundationTests" `
       -Platform $BuildPlatform `
       -Configuration $FoundationTestConfiguration `
-      -j 1
+      -j 1 # Running parallel causes a non-deterministic crash in CI only, see https://github.com/swiftlang/swift/issues/83606
   }
 }