Fix AzureDeveloperCliCredential hanging when AZD_DEBUG is set (#52013)

Author: Copilot

sdk/identity/Azure.Identity/CHANGELOG.md

@@ -8,6 +8,8 @@
 
 ### Bugs Fixed
 
+- Fixed `AzureDeveloperCliCredential` hanging when the `AZD_DEBUG` environment variable is set by adding the `--no-prompt` flag to prevent interactive prompts ([#52005](https://github.com/Azure/azure-sdk-for-net/issues/52005)).
+
 ### Other Changes
 
 ## 1.15.0 (2025-08-11)

sdk/identity/Azure.Identity/src/Credentials/AzureDeveloperCliCredential.cs

@@ -207,8 +207,8 @@ private static void GetFileNameAndArguments(string[] scopes, string tenantId, ou
             string scopeArgs = string.Join(" ", scopes.Select(scope => $"--scope {scope}"));
             string command = tenantId switch
             {
-                null => $"azd auth token --output json {scopeArgs}",
-                _ => $"azd auth token --output json {scopeArgs} --tenant-id {tenantId}"
+                null => $"azd auth token --output json --no-prompt {scopeArgs}",
+                _ => $"azd auth token --output json --no-prompt {scopeArgs} --tenant-id {tenantId}"
             };
 
             if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))

sdk/identity/Azure.Identity/tests/AzureDeveloperCliCredentialTests.cs

@@ -71,6 +71,22 @@ public async Task AuthenticateWithDeveloperCliCredential(
             }
         }
 
+        [Test]
+        public async Task AuthenticateWithDeveloperCliCredential_IncludesNoPromptFlag()
+        {
+            var context = new TokenRequestContext(new[] { Scope });
+            var (expectedToken, expectedExpiresOn, processOutput) = CredentialTestHelpers.CreateTokenForAzureDeveloperCli();
+
+            var testProcess = new TestProcess { Output = processOutput };
+            AzureDeveloperCliCredential credential =
+                InstrumentClient(new AzureDeveloperCliCredential(CredentialPipeline.GetInstance(null), new TestProcessService(testProcess, true)));
+            AccessToken actualToken = await credential.GetTokenAsync(context);
+
+            Assert.AreEqual(expectedToken, actualToken.Token);
+            Assert.AreEqual(expectedExpiresOn, actualToken.ExpiresOn);
+            Assert.That(testProcess.StartInfo.Arguments, Does.Contain("--no-prompt"));
+        }
+
         [Test]
         public void AuthenticateWithCliCredential_InvalidJsonOutput(
             [Values("", "{}", "{\"Some\": false}", "{\"token\": \"token\"}", "{\"expiresOn\" : \"1900-01-01T00:00:00Z\"}")]