Show message when Git is not found (#24402)

src/vs/workbench/parts/welcome/walkThrough/electron-browser/walkThroughPart.ts

@@ -35,10 +35,11 @@ import { IConfigurationService } from 'vs/platform/configuration/common/configur
 import { once } from 'vs/base/common/event';
 import SCMPreview from 'vs/workbench/parts/scm/browser/scmPreview';
 import { isObject } from 'vs/base/common/types';
-import { ICommandService } from 'vs/platform/commands/common/commands';
+import { ICommandService, CommandsRegistry } from 'vs/platform/commands/common/commands';
 import { ICodeEditorService } from 'vs/editor/common/services/codeEditorService';
 import { Parts, IPartService } from "vs/workbench/services/part/common/partService";
 import { IEditorOptions } from "vs/editor/common/config/editorOptions";
+import { IMessageService, Severity } from 'vs/platform/message/common/message';
 
 export const WALK_THROUGH_FOCUS = new RawContextKey<boolean>('interactivePlaygroundFocus', false);
 
@@ -102,6 +103,7 @@ export class WalkThroughPart extends BaseEditor {
 		@IContextKeyService private contextKeyService: IContextKeyService,
 		@IConfigurationService private configurationService: IConfigurationService,
 		@IModeService private modeService: IModeService,
+		@IMessageService private messageService: IMessageService,
 		@IPartService private partService: IPartService
 	) {
 		super(WalkThroughPart.ID, telemetryService, themeService);
@@ -209,6 +211,10 @@ export class WalkThroughPart extends BaseEditor {
 				from: this.input instanceof WalkThroughInput ? this.input.getTelemetryFrom() : undefined
 			});
 		}
+		if (uri.scheme === 'command' && uri.path === 'git.clone' && !CommandsRegistry.getCommand('git.clone')) {
+			this.messageService.show(Severity.Info, localize('walkThrough.gitNotFound', "It looks like Git is not installed on your system."));
+			return;
+		}
 		this.openerService.open(this.addFrom(uri));
 	}