Use the mono archive again. (#7096)

Make.config

@@ -9,12 +9,6 @@ $(TOP)/Make.config.inc: $(TOP)/Make.config
 	@printf "MAC_COMMIT_DISTANCE:=$(shell LANG=C; export LANG && git --git-dir $(TOP)/.git log `git --git-dir $(TOP)/.git blame -- ./Make.versions HEAD | grep MAC_PACKAGE_VERSION= | sed 's/ .*//' `..HEAD --oneline | wc -l | sed 's/ //g')\n" >> $@
 	@if which ccache > /dev/null 2>&1; then printf "ENABLE_CCACHE=1\nexport CCACHE_BASEDIR=$(abspath $(TOP)/..)\n" >> $@; echo "Found ccache on the system, enabling it"; fi
 	@if test -d $(TOP)/../maccore; then printf "ENABLE_XAMARIN=1\n" >> $@; echo "Detected the maccore repository, automatically enabled the Xamarin build"; fi
-	@# Build from source for Xcode 11 support until mono has packages
-	@# TODO: to be removed when we can use the mono archive again.
-ifeq ($(XI_PACKAGE),)
-	@# Don't build from source when we're using an XI package in CI (i.e. when the XI_PACKAGE variable is set - typically for device test).
-	@printf "MONO_BUILD_FROM_SOURCE=1\n" >> $@; echo "Disabled the packaged mono build, since it's currently not supported in the xcode11 support branch."
-endif
 
 include $(TOP)/Make.versions
 
@@ -49,6 +43,7 @@ IOS_PACKAGE_UPDATE_ID=$(shell printf "2%02d%02d%02d%03d" $(IOS_PACKAGE_VERSION_M
 XCODE_VERSION=11.0
 XCODE_URL=http://xamarin-storage/bot-provisioning/xcodes/Xcode_11.xip
 XCODE_DEVELOPER_ROOT=/Applications/Xcode11.app/Contents/Developer
+XCODE_PRODUCT_BUILD_VERSION:=$(shell /usr/libexec/PlistBuddy -c 'Print :ProductBuildVersion' $(XCODE_DEVELOPER_ROOT)/../version.plist)
 
 # Mono version embedded in XI/XM (NEEDED_MONO_VERSION/BRANCH) are specified in mk/mono.mk
 include $(TOP)/mk/mono.mk
@@ -339,10 +334,11 @@ JENKINS_RESULTS_DIRECTORY ?= $(abspath $(TOP)/jenkins-results)
 # Clone files instead of copying them on APFS file systems. Much faster.
 CP:=$(shell df -t apfs / >/dev/null 2>&1 && echo "cp -c" || echo "cp")
 
+XCODE_ARCHIVE_VERSION=xcode-$(XCODE_PRODUCT_BUILD_VERSION)
 MONO_IOS_FILENAME:=ios-release-Darwin-$(MONO_HASH).7z
-MONO_IOS_URL:=https://xamjenkinsartifact.azureedge.net/mono-sdks/$(MONO_IOS_FILENAME)
+MONO_IOS_URL:=https://xamjenkinsartifact.azureedge.net/mono-sdks/$(XCODE_ARCHIVE_VERSION)/$(MONO_IOS_FILENAME)
 MONO_MAC_FILENAME:=mac-release-Darwin-$(MONO_HASH).7z
-MONO_MAC_URL:=https://xamjenkinsartifact.azureedge.net/mono-sdks/$(MONO_MAC_FILENAME)
+MONO_MAC_URL:=https://xamjenkinsartifact.azureedge.net/mono-sdks/$(XCODE_ARCHIVE_VERSION)/$(MONO_MAC_FILENAME)
 
 # Setup various variables depending on whether mono is downloaded or built from source
 ifeq ($(MONO_BUILD_FROM_SOURCE),)

tools/install-source/Program.cs

@@ -207,10 +207,7 @@ public static int Main (string[] arguments)
 			}
 			if (verbose)
 				Console.WriteLine ($"Original source is {src}");
-			string fixedSource = src;
-
-			if (!File.Exists (fixedSource))
-				fixedSource = mangler.GetSourcePath (src);
+			var fixedSource = mangler.GetSourcePath (src);
 
 			if (String.IsNullOrEmpty (fixedSource)) { 
 				Console.WriteLine ($"Skip path {src}");