[dotnet] Try to implement a workaround for xamarin/maccore#2427. (#11897

)

We randomly run into a NuGet restore failure, which breaks the build, and is
quite annoying.

This might be due to a problem with multiple simultaneous restores, so this is
an attempt to first restore the packages we need, in a single serialized
restore, and once that's done we can process everything else in parallel.

Ref: xamarin/maccore#2427
Ref: NuGet/Home#10935

dotnet/Makefile

@@ -122,6 +122,9 @@ Workloads/Microsoft.NET.Sdk.$(1)/LICENSE: $(TOP)/LICENSE
 
 WORKLOAD_TARGETS += Workloads/Microsoft.NET.Sdk.$(1)/WorkloadManifest.json
 WORKLOAD_TARGETS += Workloads/Microsoft.NET.Sdk.$(1)/LICENSE
+
+LOCAL_WORKLOAD_TARGETS += Workloads/Microsoft.NET.Sdk.$(1)/WorkloadManifest.json
+LOCAL_WORKLOAD_TARGETS += Workloads/Microsoft.NET.Sdk.$(1)/LICENSE
 endef
 $(foreach platform,$(DOTNET_PLATFORMS),$(eval $(call WorkloadTargets,$(platform),$(shell echo $(platform) | tr A-Z a-z),$($(platform)_NUGET_VERSION_NO_METADATA))))
 
@@ -140,7 +143,7 @@ $(foreach platform,$(DOTNET_PLATFORMS),$(eval $(call NupkgDefinition,$(platform)
 
 # Create the nuget in a temporary directory (nupkgs/)
 define CreateNuGetTemplate
-nupkgs/$(1)$(4).$(2)+$(NUGET_BUILD_METADATA).nupkg: $(TEMPLATED_FILES) $(WORKLOAD_TARGETS) $(3) package/$(1)/package.csproj $(wildcard package/*.csproj) $(wildcard $(DOTNET_DESTDIR)/$(1)/* $(DOTNET_DESTDIR)/$(1)/*/* $(DOTNET_DESTDIR)/$(1)/*/*/* $(DOTNET_DESTDIR)/$(1)/*/*/*/*) global.json
+nupkgs/$(1)$(4).$(2)+$(NUGET_BUILD_METADATA).nupkg: $(TEMPLATED_FILES) $(WORKLOAD_TARGETS) $(3) package/$(1)/package.csproj $(wildcard package/*.csproj) $(wildcard $(DOTNET_DESTDIR)/$(1)/* $(DOTNET_DESTDIR)/$(1)/*/* $(DOTNET_DESTDIR)/$(1)/*/*/* $(DOTNET_DESTDIR)/$(1)/*/*/*/*) global.json .stamp-workaround-for-maccore-issue-2427
 	@# Delete any versions of the nuget we're building
 	$$(Q) rm -f nupkgs/$(1).*.nupkg
 	$$(Q_PACK) $(DOTNET6) pack package/$(1)/package.csproj -p:VersionBand=$(DOTNET6_VERSION_BAND) --output "$$(dir $$@)" $(DOTNET_PACK_VERBOSITY) "/bl:$$@.binlog"
@@ -153,7 +156,7 @@ nupkgs/$(1)$(4).$(2)+$(NUGET_BUILD_METADATA).nupkg: $(TEMPLATED_FILES) $(WORKLOA
 endef
 
 define CreateWindowsNuGetTemplate
-nupkgs/$(1).$(2)+$(NUGET_BUILD_METADATA).nupkg: $(3) $(WORKLOAD_TARGETS) package/$(1)/package.csproj $(wildcard package/*.csproj) $(wildcard $(DOTNET_DESTDIR)/$(1)/* $(DOTNET_DESTDIR)/$(1)/*/* $(DOTNET_DESTDIR)/$(1)/*/*/* $(DOTNET_DESTDIR)/$(1)/*/*/*/*) global.json
+nupkgs/$(1).$(2)+$(NUGET_BUILD_METADATA).nupkg: $(3) $(WORKLOAD_TARGETS) package/$(1)/package.csproj $(wildcard package/*.csproj) $(wildcard $(DOTNET_DESTDIR)/$(1)/* $(DOTNET_DESTDIR)/$(1)/*/* $(DOTNET_DESTDIR)/$(1)/*/*/* $(DOTNET_DESTDIR)/$(1)/*/*/*/*) global.json .stamp-workaround-for-maccore-issue-2427
 	@# Delete any versions of the nuget we're building
 	$$(Q) rm -f nupkgs/$(1).*.nupkg
 	$$(Q_PACK) $(DOTNET6) pack package/$(1)/package.csproj --output "$$(dir $$@)" $(DOTNET_PACK_VERBOSITY) "/bl:$$@.binlog"
@@ -387,3 +390,7 @@ Workloads/NuGet.config: $(TOP)/tests/dotnet/NuGet.config
 clean-local::
 	$(Q) rm -Rf $(DOTNET_NUPKG_DIR) $(DOTNET_FEED_DIR)
 	$(Q) git clean -xfdq
+
+.stamp-workaround-for-maccore-issue-2427: global.json $(TOP)/eng/Versions.props $(LOCAL_WORKLOAD_TARGETS)
+	$(Q) $(DOTNET6) restore package/workaround-for-maccore-issue-2427/restore.csproj /bl:package/workaround-for-maccore-issue-2427/restore.binlog $(MSBUILD_VERBOSITY)
+	$(Q) touch $@

dotnet/package/workaround-for-maccore-issue-2427/restore.csproj

@@ -0,0 +1,7 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>netstandard2.0</TargetFramework>
+  </PropertyGroup>
+  <Import Project="..\..\..\eng\Versions.props" />
+  <Import Project="Sdk.props" Sdk="Microsoft.DotNet.SharedFramework.Sdk" Version="$(MicrosoftDotNetBuildTasksFeedPackageVersion)" />
+</Project>