feat(install): add requested version to error

Signed-off-by: Mikuláš Dítě <dite@mangoweb.cz>

cmd/helm/show_test.go

@@ -49,6 +49,13 @@ func TestShowPreReleaseChart(t *testing.T) {
 			fail:        true,
 			expectedErr: "failed to download \"test/pre-release-chart\"",
 		},
+		{
+			name:        "show pre-release chart",
+			args:        "test/pre-release-chart",
+			fail:        true,
+			flags:       "--version 1.0.0",
+			expectedErr: "failed to download \"test/pre-release-chart\" at version \"1.0.0\"",
+		},
 		{
 			name:  "show pre-release chart with 'devel' flag",
 			args:  "test/pre-release-chart",

pkg/action/install.go

@@ -679,5 +679,9 @@ func (c *ChartPathOptions) LocateChart(name string, settings *cli.EnvSettings) (
 		return filename, err
 	}
 
-	return filename, errors.Errorf("failed to download %q (hint: running `helm repo update` may help)", name)
+	atVersion := ""
+	if version != "" {
+		atVersion = fmt.Sprintf(" at version %q", version)
+	}
+	return filename, errors.Errorf("failed to download %q%s (hint: running `helm repo update` may help)", name, atVersion)
 }