diff --git a/dotnet/targets/Xamarin.Shared.Sdk.targets b/dotnet/targets/Xamarin.Shared.Sdk.targets
index 37a4fe423f1b..f7329f9b6ba1 100644
--- a/dotnet/targets/Xamarin.Shared.Sdk.targets
+++ b/dotnet/targets/Xamarin.Shared.Sdk.targets
@@ -424,6 +424,9 @@
 			</_AssemblyPublishDirectories>
 			<_AssemblyPublishInputs Include="@(_AssemblyPublishDirectories -> '%(Identity)/**')" />
 		</ItemGroup>
+
+		<!-- We need to these files, so that they don't confuse incremental builds. They're only meant to convey information from an outer universal build to inner rid-specific builds, not between different outer builds. -->
+		<Delete Files="@(_ProcessedPaths)" Condition="Exists('%(Identity)')" />
 	</Target>
 
 	<Target Name="_CreateMergedAppBundle"
diff --git a/msbuild/Xamarin.Shared/Xamarin.Shared.targets b/msbuild/Xamarin.Shared/Xamarin.Shared.targets
index 630342eb12d3..b49381d49a4c 100644
--- a/msbuild/Xamarin.Shared/Xamarin.Shared.targets
+++ b/msbuild/Xamarin.Shared/Xamarin.Shared.targets
@@ -728,6 +728,7 @@ Copyright (C) 2018 Microsoft. All rights reserved.
 			_BeforeCoreCompileInterfaceDefinitions;
 			_ReadCoreCompileInterfaceDefinitions;
 			_CoreCompileInterfaceDefinitions;
+			_PostCompileInterfaceDefinitions;
 		</_CompileInterfaceDefinitionsDependsOn>
 	</PropertyGroup>
 
@@ -814,11 +815,17 @@ Copyright (C) 2018 Microsoft. All rights reserved.
 
 		<!-- Cached the generated outputs items for incremental build support -->
 		<WriteItemsToFile Items="@(_IBTool_BundleResources)" ItemName="_BundleResourceWithLogicalName" File="$(_IBToolCache)" Overwrite="true" IncludeMetadata="true" />
-		<!-- Write out the list of assets we've processed, so that an inner build in a multi-rid build can skip processing them -->
-		<WriteItemsToFile Items="@(InterfaceDefinition)" Condition="'$(_SaveProcessedItems)' == 'true'" ItemName="InterfaceDefinition" File="$(_ProcessedInterfaceDefinitionsPath)" Overwrite="true" IncludeMetadata="false" />
 
 		<ItemGroup>
 			<FileWrites Include="$(_IBToolCache)" />
+		</ItemGroup>
+	</Target>
+
+	<Target Name="_PostCompileInterfaceDefinitions">
+		<!-- Write out the list of assets we've processed, so that an inner build in a multi-rid build can skip processing them -->
+		<!-- We need to do this even for incremental builds, when we don't need to run the IBTool task, so this is not in the _CoreCompileInterfaceDefinitions target -->
+		<WriteItemsToFile Items="@(InterfaceDefinition)" Condition="'$(_SaveProcessedItems)' == 'true'" ItemName="InterfaceDefinition" File="$(_ProcessedInterfaceDefinitionsPath)" Overwrite="true" IncludeMetadata="false" />
+		<ItemGroup>
 			<FileWrites Include="$(_ProcessedInterfaceDefinitionsPath)" />
 		</ItemGroup>
 	</Target>
@@ -836,6 +843,7 @@ Copyright (C) 2018 Microsoft. All rights reserved.
 			_BeforeCoreCompileImageAssets;
 			_ReadCompileImageAssets;
 			_CoreCompileImageAssets;
+			_PostCompileImageAssets;
 		</_CompileImageAssetsDependsOn>
 	</PropertyGroup>
 
@@ -938,10 +946,16 @@ Copyright (C) 2018 Microsoft. All rights reserved.
 		<!-- Cache the generated outputs items for incremental build support -->
 		<WriteItemsToFile Items="@(_ACTool_PartialAppManifest)" ItemName="_PostCompilePartialAppManifest" File="$(_ACTool_PartialAppManifestCache)" Overwrite="true" IncludeMetadata="true" />
 		<WriteItemsToFile Items="@(_ACTool_BundleResources)" ItemName="_BundleResourceWithLogicalName" File="$(_ACTool_BundleResourceCache)" Overwrite="true" IncludeMetadata="true" />
+		<ItemGroup>
+			<FileWrites Include="$(_ACTool_PartialAppManifestCache);$(_ACTool_BundleResourceCache)" />
+		</ItemGroup>
+	</Target>
+
+	<Target Name="_PostCompileImageAssets">
 		<!-- Write out the list of assets we've processed, so that an inner build in a multi-rid build can skip processing them -->
+		<!-- We need to do this even for incremental builds, when we don't need to run the ACTool task, so this is not in the _CoreCompileImageAssets target -->
 		<WriteItemsToFile Items="@(ImageAsset)" Condition="'$(_SaveProcessedItems)' == 'true'" ItemName="ImageAsset" File="$(_ProcessedImageAssetsPath)" Overwrite="true" IncludeMetadata="false" />
 		<ItemGroup>
-			<FileWrites Include="$(_ACTool_PartialAppManifestCache);$(_ACTool_BundleResourceCache)" />
 			<FileWrites Include="$(_ProcessedImageAssetsPath)" />
 		</ItemGroup>
 	</Target>
@@ -958,6 +972,7 @@ Copyright (C) 2018 Microsoft. All rights reserved.
 			_BeforeCoreCompileSceneKitAssets;
 			_ReadCoreCompileSceneKitAssets;
 			_CoreCompileSceneKitAssets;
+			_PostCompileSceneKitAssets;
 		</_CompileSceneKitAssetsDependsOn>
 	</PropertyGroup>
 
@@ -1024,10 +1039,16 @@ Copyright (C) 2018 Microsoft. All rights reserved.
 		</CompileSceneKitAssets>
 
 		<WriteItemsToFile Items="@(_SceneKitAssets_BundleResources)" ItemName="_BundleResourceWithLogicalName" File="$(_SceneKitCache)" Overwrite="true" IncludeMetadata="true" />
+		<ItemGroup>
+			<FileWrites Include="$(_SceneKitCache)" />
+		</ItemGroup>
+	</Target>
+
+	<Target Name="_PostCompileSceneKitAssets">
 		<!-- Write out the list of assets we've processed, so that an inner build in a multi-rid build can skip processing them -->
+		<!-- We need to do this even for incremental builds, when we don't need to run the CompileSceneKitAssets task, so this is not in the SceneKitAsset target -->
 		<WriteItemsToFile Items="@(SceneKitAsset)" Condition="'$(_SaveProcessedItems)' == 'true'" ItemName="SceneKitAsset" File="$(_ProcessedSceneKitAssetsPath)" Overwrite="true" IncludeMetadata="false" />
 		<ItemGroup>
-			<FileWrites Include="$(_SceneKitCache)" />
 			<FileWrites Include="$(_ProcessedSceneKitAssetsPath)" />
 		</ItemGroup>
 	</Target>
@@ -1041,6 +1062,7 @@ Copyright (C) 2018 Microsoft. All rights reserved.
 			_BeforeCoreCompileColladaAssets;
 			_ReadCoreCompileColladaAssets;
 			_CoreCompileColladaAssets;
+			_PostCompileColladaAssets;
 		</CompileColladaAssetsDependsOn>
 	</PropertyGroup>
 
@@ -1107,10 +1129,16 @@ Copyright (C) 2018 Microsoft. All rights reserved.
 		</ScnTool>
 
 		<WriteItemsToFile Items="@(_Collada_BundleResources)" ItemName="_BundleResourceWithLogicalName" File="$(_ColladaCache)" Overwrite="true" IncludeMetadata="true" />
+		<ItemGroup>
+			<FileWrites Include="$(_ColladaCache)" />
+		</ItemGroup>
+	</Target>
+
+	<Target Name="_PostCompileColladaAssets">
 		<!-- Write out the list of assets we've processed, so that an inner build in a multi-rid build can skip processing them -->
+		<!-- We need to do this even for incremental builds, when we don't need to run the ScnTool task, so this is not in the _CoreCompileColladaAssets target -->
 		<WriteItemsToFile Items="@(Collada)" Condition="'$(_SaveProcessedItems)' == 'true'" ItemName="Collada" File="$(_ProcessedColladaAssetsPath)" Overwrite="true" IncludeMetadata="false" />
 		<ItemGroup>
-			<FileWrites Include="$(_ColladaCache)" />
 			<FileWrites Include="$(_ProcessedColladaAssetsPath)" />
 		</ItemGroup>
 	</Target>
@@ -1181,6 +1209,18 @@ Copyright (C) 2018 Microsoft. All rights reserved.
 			<_CompiledEntitlementsPath Condition="'$(_CompiledEntitlementsPath)' == ''">$(DeviceSpecificIntermediateOutputPath)Entitlements.xcent</_CompiledEntitlementsPath>
 			<_SaveProcessedItems Condition="'$(RuntimeIdentifiers)' != '' And '$(UsingAppleNETSdk)' == 'true'">true</_SaveProcessedItems>
 		</PropertyGroup>
+
+		<!-- Create an item group of all the paths that convey information from an outer (universal) build to its inner (rid-specific) builds (but not between (incremental) builds) -->
+		<ItemGroup>
+			<_ProcessedPaths Include="$(_ProcessedBundleResourcesPath)" />
+			<_ProcessedPaths Include="$(_ProcessedContentPath)" />
+			<_ProcessedPaths Include="$(_ProcessedImageAssetsPath)" />
+			<_ProcessedPaths Include="$(_ProcessedInterfaceDefinitionsPath)" />
+			<_ProcessedPaths Include="$(_ProcessedSceneKitAssetsPath)" />
+			<_ProcessedPaths Include="$(_ProcessedColladaAssetsPath)" />
+			<_ProcessedPaths Include="$(_ProcessedTextureAtlasesPath)" />
+			<_ProcessedPaths Include="$(_ProcessedCoreMLModelsPath)" />
+		</ItemGroup>
 	</Target>
 
 	<!-- TODO: check for duplicate items -->
@@ -1233,6 +1273,7 @@ Copyright (C) 2018 Microsoft. All rights reserved.
 			_BeforeCompileTextureAtlases;
 			_ReadCoreCompileTextureAtlases;
 			_CoreCompileTextureAtlases;
+			_PostCompileTextureAtlases;
 		</_CompileTextureAtlasesDependsOn>
 	</PropertyGroup>
 
@@ -1296,10 +1337,16 @@ Copyright (C) 2018 Microsoft. All rights reserved.
 
 		<!-- Cached the generated outputs items for incremental build support -->
 		<WriteItemsToFile Items="@(_TextureAtlas_BundleResources)" ItemName="_BundleResourceWithLogicalName" File="$(_TextureAtlasCache)" Overwrite="true" IncludeMetadata="true" />
+		<ItemGroup>
+			<FileWrites Include="$(_TextureAtlasCache)" />
+		</ItemGroup>
+	</Target>
+
+	<Target Name="_PostCompileTextureAtlases">
 		<!-- Write out the list of assets we've processed, so that an inner build in a multi-rid build can skip processing them -->
+		<!-- We need to do this even for incremental builds, when we don't need to run the TextureAtlas task, so this is not in the _CoreCompileTextureAtlases target -->
 		<WriteItemsToFile Items="@(AtlasTexture)" Condition="'$(_SaveProcessedItems)' == 'true'" ItemName="AtlasTexture" File="$(_ProcessedTextureAtlasesPath)" Overwrite="true" IncludeMetadata="false" />
 		<ItemGroup>
-			<FileWrites Include="$(_TextureAtlasCache)" />
 			<FileWrites Include="$(_ProcessedTextureAtlasesPath)" />
 		</ItemGroup>
 	</Target>
@@ -1391,10 +1438,16 @@ Copyright (C) 2018 Microsoft. All rights reserved.
 		<!-- Cache the generated outputs items for incremental build support -->
 		<WriteItemsToFile Items="@(_CoreMLModel_PartialAppManifest)" ItemName="_PostCompilePartialAppManifest" File="$(_CoreMLModel_PartialAppManifestCache)" Overwrite="true" IncludeMetadata="true" />
 		<WriteItemsToFile Items="@(_CoreMLModel_BundleResources)" ItemName="_BundleResourceWithLogicalName" File="$(_CoreMLModel_BundleResourceCache)" Overwrite="true" IncludeMetadata="true" />
+		<ItemGroup>
+			<FileWrites Include="$(_CoreMLModel_PartialAppManifestCache);$(_CoreMLModel_BundleResourceCache)" />
+		</ItemGroup>
+	</Target>
+
+	<Target Name="_PostCompileCoreMLModels">
 		<!-- Write out the list of assets we've processed, so that an inner build in a multi-rid build can skip processing them -->
+		<!-- We need to do this even for incremental builds, when we don't need to run the CoreMLCompiler task, so this is not in the _CoreCompileCoreMLModels target -->
 		<WriteItemsToFile Items="@(CoreMLModel)" Condition="'$(_SaveProcessedItems)' == 'true'" ItemName="CoreMLModel" File="$(_ProcessedCoreMLModelsPath)" Overwrite="true" IncludeMetadata="false" />
 		<ItemGroup>
-			<FileWrites Include="$(_CoreMLModel_PartialAppManifestCache);$(_CoreMLModel_BundleResourceCache)" />
 			<FileWrites Include="$(_ProcessedCoreMLModelsPath)" />
 		</ItemGroup>
 	</Target>
diff --git a/tools/devops/automation/scripts/System.psm1 b/tools/devops/automation/scripts/System.psm1
index 5b67f2f7a4f2..d9bad3e0258c 100644
--- a/tools/devops/automation/scripts/System.psm1
+++ b/tools/devops/automation/scripts/System.psm1
@@ -251,7 +251,7 @@ function Assert-HDFreeSpace {
 
     Write-Host ""
 
-    $stepUrl = "$Env:SYSTEM_TEAMFOUNDATIONCOLLECTIONURI$Env:SYSTEM_TEAMPROJECT/results?buildId=$Env:BUILD_BUILDID&view=logs&j=$Env:SYSTEM_JOBIDENTIFIER&t=$Env:SYSTEM_TASKINSTANCEID"
+    $stepUrl = "$Env:SYSTEM_TEAMFOUNDATIONCOLLECTIONURI$Env:SYSTEM_TEAMPROJECT/_build/results?buildId=$Env:BUILD_BUILDID&view=logs&j=$Env:SYSTEM_JOBID&t=$Env:SYSTEM_TASKINSTANCEID"
     $workItemTitle = "[CI] Bot '$Env:AGENT_MACHINENAME' out of disk space"
     $workItemMessage = @"
 <div>The bot <b>$Env:AGENT_MACHINENAME</b> does not have enough hard disk space left.</div>
diff --git a/tools/devops/automation/scripts/bash/build-nugets.sh b/tools/devops/automation/scripts/bash/build-nugets.sh
index 8f469722b4dd..b133aa2da864 100755
--- a/tools/devops/automation/scripts/bash/build-nugets.sh
+++ b/tools/devops/automation/scripts/bash/build-nugets.sh
@@ -10,8 +10,8 @@ cd "$XAM_TOP"
 
 DOTNET_NUPKG_DIR=$(make -C tools/devops print-abspath-variable VARIABLE=DOTNET_NUPKG_DIR | grep "^DOTNET_NUPKG_DIR=" | sed -e 's/^DOTNET_NUPKG_DIR=//')
 
+rm -rf ../package/
 mkdir -p ../package/
-rm -f ../package/*.nupkg
 cp -c "$DOTNET_NUPKG_DIR"/*.nupkg ../package/
 cp -c "$DOTNET_NUPKG_DIR"/vs-workload.props ../package/
 cp -c dotnet/Workloads/SignList.xml ../package/
diff --git a/tools/devops/automation/scripts/bash/clean-bot.sh b/tools/devops/automation/scripts/bash/clean-bot.sh
index c48e4d5895f7..07e0adc41bb7 100755
--- a/tools/devops/automation/scripts/bash/clean-bot.sh
+++ b/tools/devops/automation/scripts/bash/clean-bot.sh
@@ -14,11 +14,27 @@ set +e
 
 # Clean workspace
 (
-	REPO_PATH="SYSTEM_DEFAULTWORKINGDIRECTORY/$(basename "$BUILD_REPOSITORY_NAME")"
-	if test -d "$REPO_PATH"; then
-		cd "$REPO_PATH"
-		git clean -xfd
-	fi
+	for repo in "$SYSTEM_DEFAULTWORKINGDIRECTORY"/.git "$SYSTEM_DEFAULTWORKINGDIRECTORY"/*/.git; do
+		if test -d "$repo"; then
+			cd "$repo"
+			cd ..
+			echo "Running 'git clean' (for all submodules too) in $(pwd)"
+			git clean -xffd | sed 's/^/    /' || true
+			git submodule foreach --recursive git clean -xffd | sed 's/^/    /' || true
+		else
+			echo "$repo is not a git repository"
+		fi
+	done
+
+	echo "Cleaning packages directory:"
+	rm -rv "$SYSTEM_DEFAULTWORKINGDIRECTORY/packages" | sed 's/^/    /' || true
+
+	echo "Contents of SYSTEM_DEFAULTWORKINGDIRECTORY ($SYSTEM_DEFAULTWORKINGDIRECTORY):"
+	# shellcheck disable=SC2012
+	ls -la "$SYSTEM_DEFAULTWORKINGDIRECTORY" | sed 's/^/    /' || true
+	echo "Contents of BUILD_SOURCESDIRECTORY ($BUILD_SOURCESDIRECTORY):"
+	# shellcheck disable=SC2012
+	ls -la "$BUILD_SOURCESDIRECTORY" | sed 's/^/    /' || true
 )
 
 # Delete all the simulator devices. These can take up a lot of space over time (I've seen 100+GB on the bots)