Add error message if prune package data can't be found, and add prope…

…rty to allow missing data

src/Tasks/Common/Resources/Strings.resx

@@ -978,9 +978,12 @@ You may need to build the project on another operating system or architecture, o
     <value>NETSDK1224: ASP.NET Core framework assets are not supported for the target framework.</value>
     <comment>{StrBegins="NETSDK1224: "}</comment>
   </data>
-  <!-- The latest message added is NativeCompilationRequiresPublishing. Please update this value with each PR to catch parallel PRs both adding a new message -->
   <data name="NativeCompilationRequiresPublishing" xml:space="preserve">
     <value>NETSDK1225: Native compilation is not supported when invoking the Publish target directly. Try running dotnet publish.</value>
     <comment>{StrBegins="NETSDK1225: "}</comment>
   </data>
+  <!-- The latest message added is PrunePackageDataNotFound. Please update this value with each PR to catch parallel PRs both adding a new message -->
+  <data name="PrunePackageDataNotFound" xml:space="preserve">
+    <value>NETSDK1226: Prune Package data not found {0} {1} {2}.  To ignore this error, set the AllowMissingPrunePackageData to true.</value>
+  </data>
 </root>

src/Tasks/Microsoft.NET.Build.Tasks/GetPackagesToPrune.cs

@@ -32,6 +32,9 @@ public class GetPackagesToPrune : TaskBase
         [Required]
         public string PrunePackageDataRoot { get; set; }
 
+        [Required]
+        public bool AllowMissingPrunePackageData { get; set; }
+
         [Output]
         public ITaskItem[] PackagesToPrune { get; set; }
 
@@ -110,12 +113,12 @@ protected override void ExecuteCore()
                 return;
             }
 
-            PackagesToPrune = LoadPackagesToPrune(key, TargetingPackRoots, PrunePackageDataRoot, Log);
+            PackagesToPrune = LoadPackagesToPrune(key, TargetingPackRoots, PrunePackageDataRoot, Log, AllowMissingPrunePackageData);
 
             BuildEngine4.RegisterTaskObject(key, PackagesToPrune, RegisteredTaskObjectLifetime.Build, true);
         }
 
-        static TaskItem[] LoadPackagesToPrune(CacheKey key, string[] targetingPackRoots, string prunePackageDataRoot, Logger log)
+        static TaskItem[] LoadPackagesToPrune(CacheKey key, string[] targetingPackRoots, string prunePackageDataRoot, Logger log, bool allowMissingPrunePackageData)
         {
             Dictionary<string, NuGetVersion> packagesToPrune = new();
 
@@ -185,10 +188,20 @@ static TaskItem[] LoadPackagesToPrune(CacheKey key, string[] targetingPackRoots,
                     //  We didn't find the data for packages to prune.  This indicates that there's a bug in the SDK construction, so fail hard here so that we fix that
                     //  (rather than a warning that might be missed).
                     //  Since this indicates an error in the SDK build, the message probably doesn't need to be localized.
-                    throw new Exception($"Prune package data not found for {key.TargetFrameworkIdentifier} {key.TargetFrameworkVersion} {frameworkReference}");
-                }
 
-                AddPackagesToPrune(packagesToPrune, packagesForFrameworkReference.Select(kvp => (kvp.Key, kvp.Value)), log);
+                    if (allowMissingPrunePackageData)
+                    {
+                        log.LogMessage($"Prune package data not found for {key.TargetFrameworkIdentifier} {key.TargetFrameworkVersion} {frameworkReference}");
+                    }
+                    else
+                    {
+                        log.LogError(Strings.PrunePackageDataNotFound, key.TargetFrameworkIdentifier, key.TargetFrameworkVersion, frameworkReference);
+                    }
+                }
+                else
+                {
+                    AddPackagesToPrune(packagesToPrune, packagesForFrameworkReference.Select(kvp => (kvp.Key, kvp.Value)), log);
+                }
             }
 
             return packagesToPrune.Select(p =>

src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.Sdk.FrameworkReferenceResolution.targets

@@ -58,14 +58,16 @@ Copyright (c) .NET Foundation. All rights reserved.
     <PropertyGroup>
       <PrunePackageDataRoot Condition="'$(PrunePackageDataRoot)' == ''">$(NetCoreRoot)\sdk\$(NETCoreSdkVersion)\PrunePackageData\</PrunePackageDataRoot>
       <PrunePackageTargetingPackRoots Condition="'$(PrunePackageTargetingPackRoots)' == ''">$(NetCoreTargetingPackRoot)</PrunePackageTargetingPackRoots>
+      <AllowMissingPrunePackageData Condition="'$(AllowMissingPrunePackageData)' == ''">false</AllowMissingPrunePackageData>
     </PropertyGroup>
 
     <GetPackagesToPrune TargetFrameworkIdentifier="$(TargetFrameworkIdentifier)"
                         TargetFrameworkVersion="$(_TargetFrameworkVersionWithoutV)"
                         FrameworkReferences="@(FrameworkReference)"
                         TargetingPacks="@(TargetingPack)"
                         TargetingPackRoots="$(PrunePackageTargetingPackRoots)"
-                        PrunePackageDataRoot="$(PrunePackageDataRoot)">
+                        PrunePackageDataRoot="$(PrunePackageDataRoot)"
+                        AllowMissingPrunePackageData="$(AllowMissingPrunePackageData)">
       <Output TaskParameter="PackagesToPrune" ItemName="PrunePackageReference" />
     </GetPackagesToPrune>