Workloads: fix CI build when bumping to a newer version band

To resolve a workload, the current version band is used to look in
`sdk-manifests` directory. But when in development, and bumping to a
newer version band, not all the manifests might have packages for that.

This shows up when bumping the band to `6.0.200`, where we generate
the corresponding packages for wasm-tools. But the Emscripten packages
are still on `6.0.100`.

SDK [added](dotnet/sdk#19545) support for
falling back to older bands in that case.

The `InstallWorkloadFromArtifacts` task emits a warning about not being
able to find the emscripten manifest package. But this becomes an error
on CI due to warnaserror=true.

So, log a message instead of a warning. But this is only done for the
*dependent* manifest.

Author: radical

src/tasks/WorkloadBuildTasks/InstallWorkloadFromArtifacts.cs

@@ -92,7 +92,7 @@ public override bool Execute()
 
         private bool InstallWorkloadManifest(string name, string version, string nugetConfigContents, bool stopOnMissing)
         {
-            Log.LogMessage(MessageImportance.High, $"Installing workload manifest for {name}/{version}");
+            Log.LogMessage(MessageImportance.High, $"Installing workload manifest for {name}/{version} for sdk band {VersionBand}");
 
             // Find any existing directory with the manifest name, ignoring the case
             // Multiple directories for a manifest, differing only in case causes
@@ -145,7 +145,15 @@ private bool InstallWorkloadManifest(string name, string version, string nugetCo
                 {
                     if (!InstallWorkloadManifest(depName, depVersion, nugetConfigContents, stopOnMissing: false))
                     {
-                        Log.LogWarning($"Could not install manifest {depName}/{depVersion}. This can be ignored if the workload {WorkloadId.ItemSpec} doesn't depend on it.");
+                        Log.LogMessage(MessageImportance.High,
+                                                $" ***** warning ******{Environment.NewLine}" +
+                                                Environment.NewLine +
+                                                $"Could not install a dependent manifest {depName}/{depVersion} for sdk band {VersionBand}.{Environment.NewLine}" +
+                                                $"If this is because this manifest doesn't have a package for sdk band {VersionBand}, " +
+                                                $"then the workload resolver will automatically fallback to the older one, and this message can be ignored.{Environment.NewLine}" +
+                                                $"This can also be safely ignored if the workload {WorkloadId.ItemSpec} doesn't use the dependency.{Environment.NewLine}" +
+                                                Environment.NewLine +
+                                                $" ********************{Environment.NewLine}");
                         continue;
                     }
                 }

src/tasks/WorkloadBuildTasks/PackageInstaller.cs

@@ -63,7 +63,7 @@ private bool InstallActual(PackageReference[] references, bool stopOnMissing)
             (int exitCode, string output) = Utils.TryRunProcess(_logger, "dotnet", args, silent: false, debugMessageImportance: MessageImportance.Low);
             if (exitCode != 0)
             {
-                LogErrorOrWarning($"Restoring packages failed with exit code: {exitCode}. Output:{Environment.NewLine}{output}", stopOnMissing);
+                LogFailure($"Restoring packages failed with exit code: {exitCode}. Output:{Environment.NewLine}{output}", stopOnMissing);
                 return false;
             }
 
@@ -76,7 +76,7 @@ private bool InstallActual(PackageReference[] references, bool stopOnMissing)
             {
                 _logger.LogMessage(MessageImportance.Normal, output);
                 foreach ((PackageReference pkgRef, string pkgDir) in failedToRestore)
-                    LogErrorOrWarning($"Could not restore {pkgRef.Name}/{pkgRef.Version} (can't find {pkgDir})", stopOnMissing);
+                    LogFailure($"Could not restore {pkgRef.Name}/{pkgRef.Version} (can't find {pkgDir})", stopOnMissing);
 
                 return false;
             }
@@ -91,7 +91,7 @@ private bool LayoutPackages(IEnumerable<PackageReference> references, bool stopO
                 var source = Path.Combine(_packagesDir, pkgRef.Name.ToLower(), pkgRef.Version, pkgRef.relativeSourceDir);
                 if (!Directory.Exists(source))
                 {
-                    LogErrorOrWarning($"Failed to restore {pkgRef.Name}/{pkgRef.Version} (could not find {source})", stopOnMissing);
+                    LogFailure($"Failed to restore {pkgRef.Name}/{pkgRef.Version} (could not find {source})", stopOnMissing);
                     if (stopOnMissing)
                         return false;
                 }
@@ -152,12 +152,12 @@ private bool CopyDirectoryAfresh(string srcDir, string destDir)
             }
         }
 
-        private void LogErrorOrWarning(string msg, bool stopOnMissing)
+        private void LogFailure(string msg, bool asError)
         {
-            if (stopOnMissing)
+            if (asError)
                 _logger.LogError(msg);
             else
-                _logger.LogWarning(msg);
+                _logger.LogMessage(MessageImportance.High, $"warning: {msg}");
         }
     }
 }