[Core] Continue on error when resolving package dependencies.

Set ContinueOnError=ErrorAndContinue when running the MSBuild target
ResolvePackageDependenciesDesignTime. This allows the target to
run even if one of other MSBuild targets fails. For example, an
unknown PackageReference may cause this to fail unless continue on
error is set.

Author: mrward

main/src/core/MonoDevelop.Core/MonoDevelop.Projects/DotNetProject.cs

@@ -1201,6 +1201,9 @@ async Task<List<PackageDependency>> RunResolvePackageDependenciesTarget (Configu
 				context.BuilderQueue = BuilderQueue.ShortOperations;
 				context.LoadReferencedProjects = false;
 				context.LogVerbosity = MSBuildVerbosity.Quiet;
+				// Even though some targets may fail it may still be possible for the main resolve target to return
+				// information so we set ContinueOnError. This matches VS on Windows behaviour.
+				context.GlobalProperties.SetValue ("ContinueOnError", "ErrorAndContinue");
 
 				var result = await RunTargetInternal (monitor, "ResolvePackageDependenciesDesignTime", configuration, context);
 

main/tests/MonoDevelop.Core.Tests/MonoDevelop.Projects/ProjectTests.cs

@@ -1126,10 +1126,13 @@ public async Task UnknownNuGetPackageReferenceId_DesignTimeBuilds ()
 
 			using (var sol = (Solution)await Services.ProjectService.ReadWorkspaceItem (Util.GetMonitor (), solFile)) {
 				var project = sol.GetAllProjects ().Single () as DotNetProject;
-				var refs = (await project.GetReferencedAssemblies (ConfigurationSelector.Default)).ToArray ();
+				var references = (await project.GetReferencedAssemblies (ConfigurationSelector.Default)).ToArray ();
+				var packageDependencies = (await project.GetPackageDependencies (ConfigurationSelector.Default, CancellationToken.None)).ToArray ();
 
-				Assert.IsTrue (refs.Any ());
-				Assert.IsTrue (refs.Any (r => r.FilePath.FileName == "Newtonsoft.Json.dll"));
+				Assert.IsTrue (references.Any ());
+				Assert.IsTrue (references.Any (r => r.FilePath.FileName == "Newtonsoft.Json.dll"));
+				Assert.IsTrue (packageDependencies.Any ());
+				Assert.IsTrue (packageDependencies.Any (p => p.Name == "Newtonsoft.Json"));
 			}
 		}