.NET: Report plugin install errors during pulumi new (#5760)

The way `pulumi new` installs dependencies for .NET projects is slightly different from other languages. For Node.js, Python, and Go, `pulumi new` runs the appropriate command to install project dependencies (e.g. `npm install`, `pip install`, or `go mod download`). For .NET, it calls the same routine used during `preview|up` to ensure required plugins are installed. For .NET, this ends up running `dotnet build` which implicitly installs Nuget packages, builds the project, and also attempts to determine and install the needed Pulumi plugins. When this operation runs during `preview|up`, and there are failures installing a plugin, the error is logged, but deliberately not returned, because an error will be shown for missing plugins later on during the `preview|up` operation. However, during `pulumi new`, we should show any plugin install errors.

CHANGELOG.md

@@ -33,6 +33,9 @@ CHANGELOG
 - Fix plugin install failures on Windows.
   [#5759](https://github.com/pulumi/pulumi/pull/5759)
 
+- .NET: Report plugin install errors during `pulumi new`.
+  [#5760](https://github.com/pulumi/pulumi/pull/5760)
+
 ## 2.13.2 (2020-11-06)
 
 - Fix a bug that was causing errors when (de)serializing custom resources.

pkg/engine/plan.go

@@ -167,7 +167,8 @@ func plan(ctx *Context, info *planContext, opts planOptions, dryRun bool) (*plan
 		plan, err = deploy.NewPlan(
 			plugctx, target, target.Snapshot, source, localPolicyPackPaths, dryRun, ctx.BackendClient)
 	} else {
-		_, defaultProviderVersions, pluginErr := installPlugins(proj, pwd, main, target, plugctx)
+		_, defaultProviderVersions, pluginErr := installPlugins(proj, pwd, main, target, plugctx,
+			false /*returnInstallErrors*/)
 		if pluginErr != nil {
 			return nil, pluginErr
 		}

pkg/engine/plugins.go

@@ -19,6 +19,7 @@ import (
 	"sort"
 
 	"github.com/blang/semver"
+	"github.com/pkg/errors"
 	"golang.org/x/sync/errgroup"
 
 	"github.com/pulumi/pulumi/pkg/v2/resource/deploy"
@@ -181,7 +182,8 @@ func installPlugin(plugin workspace.PluginInfo) error {
 	logging.V(preparePluginVerboseLog).Infof(
 		"installPlugin(%s, %s): extracting tarball to installation directory", plugin.Name, plugin.Version)
 	if err := plugin.Install(stream); err != nil {
-		return err
+		return errors.Wrapf(err, "installing plugin; run `pulumi plugin install %s %s v%s` to retry manually",
+			plugin.Kind, plugin.Name, plugin.Version)
 	}
 
 	logging.V(7).Infof("installPlugin(%s, %s): successfully installed", plugin.Name, plugin.Version)

pkg/engine/query.go

@@ -93,7 +93,7 @@ func newQuerySource(cancel context.Context, client deploy.BackendClient, q Query
 	opts QueryOptions) (deploy.QuerySource, error) {
 
 	allPlugins, defaultProviderVersions, err := installPlugins(q.GetProject(), opts.pwd, opts.main,
-		nil, opts.plugctx)
+		nil, opts.plugctx, false /*returnInstallErrors*/)
 	if err != nil {
 		return nil, err
 	}

pkg/engine/update.go

@@ -189,13 +189,13 @@ func Update(u UpdateInfo, ctx *Context, opts UpdateOptions, dryRun bool) (Resour
 // RunInstallPlugins calls installPlugins and just returns the error (avoids having to export pluginSet).
 func RunInstallPlugins(
 	proj *workspace.Project, pwd, main string, target *deploy.Target, plugctx *plugin.Context) error {
-	_, _, err := installPlugins(proj, pwd, main, target, plugctx)
+	_, _, err := installPlugins(proj, pwd, main, target, plugctx, true /*returnInstallErrors*/)
 	return err
 }
 
 func installPlugins(
 	proj *workspace.Project, pwd, main string, target *deploy.Target,
-	plugctx *plugin.Context) (pluginSet, map[tokens.Package]*semver.Version, error) {
+	plugctx *plugin.Context, returnInstallErrors bool) (pluginSet, map[tokens.Package]*semver.Version, error) {
 
 	// Before launching the source, ensure that we have all of the plugins that we need in order to proceed.
 	//
@@ -227,8 +227,12 @@ func installPlugins(
 	// If there are any plugins that are not available, we can attempt to install them here.
 	//
 	// Note that this is purely a best-effort thing. If we can't install missing plugins, just proceed; we'll fail later
-	// with an error message indicating exactly what plugins are missing.
+	// with an error message indicating exactly what plugins are missing. If `returnInstallErrors` is set, then return
+	// the error.
 	if err := ensurePluginsAreInstalled(allPlugins); err != nil {
+		if returnInstallErrors {
+			return nil, nil, err
+		}
 		logging.V(7).Infof("newUpdateSource(): failed to install missing plugins: %v", err)
 	}
 
@@ -356,7 +360,7 @@ func newUpdateSource(
 	//
 
 	allPlugins, defaultProviderVersions, err := installPlugins(proj, pwd, main, target,
-		plugctx)
+		plugctx, false /*returnInstallErrors*/)
 	if err != nil {
 		return nil, err
 	}