Close guest process stdin to avoid TTY hang on macOS

[spboyer]

Description

aspire new for the TypeScript starter (and aspire init/add/restore) hangs silently on macOS, producing no further output at ~0% CPU. Issue #16791 documents the symptom and a working < /dev/null workaround, which is strong evidence that some spawned child inherits the parent CLI's TTY and blocks on a stdin read.

Root cause

Several subprocess launch paths in Aspire.Cli set RedirectStandardOutput/Error = true and UseShellExecute = false, but leave stdin inheriting the parent TTY. On macOS/Linux any read from stdin in those children then blocks forever:

Launch path	Used for
ProcessGuestLauncher	npm/pnpm/yarn/bun install (and the guest AppHost itself)
NpmRunner	npm view / pack / audit signatures / install -g
DotNetBasedAppHostServerProject.Run	Dev/source-based AppHost server process
PrebuiltAppHostServer.CreateStartInfo	Shipped AppHost server process

The TypeScript starter flow exercises all of these via BuildAndGenerateSdkAsync: prepare → start AppHost server → RPC codegen → npm install. By contrast, dotnet new install already goes through ProcessExecutionFactory, which sets RedirectStandardInput = true — that's why C#-only template scaffolding doesn't hit this.

Fix

In each of the four launch paths above:

1. Set RedirectStandardInput = true on the ProcessStartInfo.
2. Immediately after process.Start(), call process.StandardInput.Close() (wrapped in try/catch (IOException)) so any child read surfaces as EOF instead of blocking on the inherited TTY.

The CLI controls these processes via Ctrl+C / backchannel cancellation and Unix-socket IPC (REMOTE_APP_HOST_SOCKET_PATH), never via stdin, so closing the pipe is safe.

Tests

Added ProcessGuestLauncher_ClosesChildStdinSoReadsObserveEof in GuestRuntimeTests. It launches a short shell snippet that reads stdin and asserts the launcher returns within 10s with the child reporting EOF. Without the fix the test would block on the inherited TTY (or be killed by the 10s CTS).

All GuestRuntimeTests, AppHostServerProjectTests, AppHostServerSessionTests, and NpmRunnerTests pass locally (49 succeeded, 4 Windows-only skipped).

Fixes #16791

[github-actions]

🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://raw.githubusercontent.com/microsoft/aspire/main/eng/scripts/get-aspire-cli-pr.sh | bash -s -- 17562

Or

• Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/microsoft/aspire/main/eng/scripts/get-aspire-cli-pr.ps1) } 17562"

[Copilot]

Pull request overview

Fixes a macOS/Linux hang in Aspire CLI guest process execution (notably TypeScript scaffolding flows) by ensuring spawned child processes do not inherit the parent TTY for stdin, preventing lifecycle scripts or prompts from blocking indefinitely.

Changes:

• Redirect and immediately close stdin for guest processes launched via ProcessGuestLauncher so child reads observe EOF instead of blocking on the terminal.
• Apply the same stdin redirect+close behavior to NpmRunner subprocess invocations.
• Add a regression test that launches a command which attempts to read stdin and asserts it exits promptly with EOF observed.

Show a summary per file

File	Description
tests/Aspire.Cli.Tests/Projects/GuestRuntimeTests.cs	Adds regression coverage ensuring child stdin is closed so reads return EOF (prevents macOS TTY hangs).
src/Aspire.Cli/Projects/ProcessGuestLauncher.cs	Redirects stdin and closes it immediately after start to avoid inheriting the CLI’s TTY.
src/Aspire.Cli/Npm/NpmRunner.cs	Redirects stdin for npm processes and closes it right after start to prevent interactive hangs.

Copilot's findings

• Files reviewed: 3/3 changed files
• Comments generated: 0

[spboyer]

The \Cli.EndToEnd-EmptyAppHostTemplateTests\ failure (C# empty AppHost) looks like a flaky E2E test rather than a regression from this PR:

• The changes in this PR only affect TypeScript/npm guest process launching (\ProcessGuestLauncher, \NpmRunner) and the code-gen AppHost server (\DotNetBasedAppHostServerProject, \PrebuiltAppHostServer). They do not touch the C# AppHost runtime used by \�spire start/\�spire stop.
• The TypeScript variant of the same test (\TypeScriptEmptyAppHostTemplateTests) passed ✅ — confirming the TypeScript path is healthy.
• The failure is \�spire stop\ timing out after 8:20 while waiting for the apphost to stop — a known infrastructure flakiness pattern for this test suite.

Will request a re-run once the current CI run completes.

[github-actions]

Re-running the failed jobs in the CI workflow for this pull request because 1 job was identified as retry-safe transient failures in the CI run attempt.
GitHub was asked to rerun all failed jobs for that attempt, and the rerun is being tracked in the rerun attempt.
The job links below point to the failed attempt jobs that matched the retry-safe transient failure rules.

• Tests / Hosting-1 / Hosting-1 (windows-latest) - Job-level runner or infrastructure failure matched the transient allowlist.

[github-actions]

Re-running the failed jobs in the CI workflow for this pull request because 1 job was identified as retry-safe transient failures in the CI run attempt.
GitHub was asked to rerun all failed jobs for that attempt, and the rerun is being tracked in the rerun attempt.
The job links below point to the failed attempt jobs that matched the retry-safe transient failure rules.

• Tests / Acquisition / Acquisition (macos-latest) - Failed step 'Build test project' will be retried because the job log shows a likely transient infrastructure network failure. Matched pattern: /Unable to load the service index for source https:\/\/(?:pkgs\.dev\.azure\.com\/dnceng|dnceng\.pkgs\.visualstudio\.com)\/public\/_packaging\//i.

[github-actions]

❓ CLI E2E Tests unknown — 107 passed, 0 failed, 2 unknown (commit ee36829)

View all recordings

Status	Test	Recording	Job	Artifacts
✅	AddPackageInteractiveWhileAppHostRunningDetached	Recording	#78428599143	Logs
✅	AddPackageWhileAppHostRunningDetached	Recording	#78428599143	Logs
✅	AgentCommands_AllHelpOutputs_AreCorrect	Recording	#78428599387	Logs
✅	AgentInitCommand_DefaultSelection_InstallsDefaultSkills	Recording	#78428599387	Logs
✅	AgentInitCommand_MigratesDeprecatedConfig	Recording	#78428599387	Logs
✅	AgentMcpListStructuredLogsReturnsLogsFromStarterApp	Recording	#78428599281	Logs
✅	AgentMcpListStructuredLogsReturnsLogsFromStarterApp_DevLocalhost	Recording	#78428599281	Logs
✅	AgentMcpListStructuredLogsReturnsLogsFromStarterApp_Isolated	Recording	#78428599281	Logs
✅	AllPublishMethodsBuildDockerImages	Recording	#78428599296	Logs
✅	AspireAddAndStartWorkAgainstLegacyAppHostTs	Recording	#78428599017	Logs
✅	AspireAddPackageVersionToDirectoryPackagesProps	Recording	#78428599229	Logs
✅	AspireInitSingleFileAppHostRunsViaDotnetRunAppHost	Recording	#78428598748	Logs
✅	AspireInitWithExistingAppHostDirRecreatesMissingNuGetConfigAndPreservesFiles	Recording	#78428599279	Logs
❔	AspireInitWithSolutionFileGeneratesAppHostThatBuildsAgainstChannelHive	Recording	#78428599279	Logs
✅	AspireStartUpdatesStaleTypeScriptAppHostPath	Recording	#78428598909	Logs
✅	AspireUpdateRemovesAppHostPackageVersionFromDirectoryPackagesProps	Recording	#78428599229	Logs
✅	AspireUpdateRemovesOrphanAppHostPackageVersionWhenSdkAlreadyCurrent	Recording	#78428599229	Logs
✅	Banner_DisplayedOnFirstRun	Recording	#78428598933	Logs
✅	Banner_DisplayedWithExplicitFlag	Recording	#78428598933	Logs
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✅	ConfigSetGet_CreatesNestedJsonFormat	Recording	#78428599439	Logs
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✅	CreateAndRunPythonReactProject	Recording	#78428599315	Logs
✅	CreateAndRunTypeScriptEmptyAppHostProject	Recording	#78428599305	Logs
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✅	CreateJavaAppHostWithViteApp	Recording	#78428598972	Logs
✅	CreateTypeScriptAppHostWithViteApp_AllowsGuestAppPackageManagerToDiffer	Recording	#78428598946	Logs
✅	CreateTypeScriptAppHostWithViteApp_UsesConfiguredToolchain	Recording	#78428598946	Logs
✅	DashboardRunWithAgentMcpListTracesReturnsNoTraces	Recording	#78428599327	Logs
✅	DashboardRunWithAgentMcpListTracesReturnsNoTraces_DevLocalhost	Recording	#78428599327	Logs
✅	DashboardRunWithOtelTracesReturnsNoTraces	Recording	#78428599327	Logs
✅	DashboardRunWithOtelTracesReturnsNoTraces_DevLocalhost	Recording	#78428599327	Logs
✅	DeployK8sBasicApiService	Recording	#78428599054	Logs
✅	DeployK8sWithExternalHelmChart	Recording	#78428598913	Logs
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✅	DeployK8sWithPostgres	Recording	#78428599287	Logs
✅	DeployK8sWithRabbitMQ	Recording	#78428599316	Logs
✅	DeployK8sWithRedis	Recording	#78428599277	Logs
✅	DeployK8sWithSqlServer	Recording	#78428599297	Logs
✅	DeployK8sWithValkey	Recording	#78428599309	Logs
✅	DeployTypeScriptAppToKubernetes	Recording	#78428599104	Logs
✅	DescribeCommandResolvesReplicaNames	Recording	#78428599301	Logs
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✅	DetachFormatJsonProducesValidJson	Recording	#78428599070	Logs
✅	DetachFormatJsonProducesValidJsonWhenRestartingExistingInstance	Recording	#78428599070	Logs
✅	DoPublishAndDeployListStepsWork	Recording	#78428598796	Logs
✅	DocsCommand_RendersInteractiveMarkdownFromLocalSource	Recording	#78428598969	Logs
✅	DoctorCommand_DetectsDeprecatedAgentConfig	Recording	#78428599387	Logs
✅	DoctorCommand_TypeScriptAppHostReportsMissingConfiguredToolchain	Recording	#78428599072	Logs
✅	DoctorCommand_WithSslCertDir_ShowsTrusted	Recording	#78428599072	Logs
✅	DoctorCommand_WithoutSslCertDir_ShowsPartiallyTrusted	Recording	#78428599072	Logs
✅	GatewayWithoutExternalEndpoint_FailsPublishWithGuidance	Recording	#78428599019	Logs
✅	GeneratedAspireDevScript_StartsWatchMode_WithConfiguredToolchain	Recording	#78428598946	Logs
✅	GlobalMigration_HandlesCommentsAndTrailingCommas	Recording	#78428599439	Logs
✅	GlobalMigration_HandlesMalformedLegacyJson	Recording	#78428599439	Logs
✅	GlobalMigration_PreservesAllValueTypes	Recording	#78428599439	Logs
✅	GlobalMigration_SkipsWhenNewConfigExists	Recording	#78428599439	Logs
✅	GlobalSettings_MigratedFromLegacyFormat	Recording	#78428599439	Logs
✅	IngressWithoutExternalEndpoint_FailsPublishWithGuidance	Recording	#78428599019	Logs
✅	InitTypeScriptAppHost_AugmentsExistingViteRepoInWorkspaceSubdirectory	Recording	#78428598946	Logs
✅	InteractiveCSharpInitCreatesExpectedFiles	Recording	#78428598993	Logs
✅	InvalidAppHostPathWithComments_IsHealedOnRun	Recording	#78428598984	Logs
✅	JavaScriptHostingApisRunFromTypeScriptAppHost	Recording	#78428599296	Logs
✅	LatestCliCanStartStableChannelAppHost	Recording	#78428599045	Logs
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✅	LegacySettingsMigration_AdjustsRelativeAppHostPath	Recording	#78428598909	Logs
✅	LogsCommandShowsResourceLogs	Recording	#78428598866	Logs
✅	OtelLogsReturnsStructuredLogsFromStarterApp	Recording	#78428598723	Logs
✅	OtelLogsReturnsStructuredLogsFromStarterAppIsolated	Recording	#78428598723	Logs
✅	PsCommandListsRunningAppHost	Recording	#78428599306	Logs
✅	PsFormatJsonOutputsOnlyJsonToStdout	Recording	#78428599306	Logs
✅	PublishJavaScriptPatternsGeneratesExpectedDockerComposeArtifacts	Recording	#78428599383	Logs
✅	PublishWithConfigureEnvFileUpdatesEnvOutput	Recording	#78428599383	Logs
✅	PublishWithDockerComposeServiceCallbackSucceeds	Recording	#78428599383	Logs
✅	PublishWithoutOutputPathUsesAppHostDirectoryDefault	Recording	#78428599383	Logs
✅	ResourceCommand_FailedExecution_DisplaysAppHostLogPathAndLogContainsEntries	Recording	#78428599200	Logs
✅	ResourceCommand_SetAndDeleteParameterUpdatesDescribeOutput	Recording	#78428599200	Logs
✅	RestoreGeneratesSdkFiles	Recording	#78428599167	Logs
✅	RestoreGeneratesSdkFiles_WithConfiguredToolchain	Recording	#78428599284	Logs
✅	RestoreRefreshesGeneratedSdkAfterAddingIntegration	Recording	#78428599284	Logs
✅	RestoreSupportsConfigOnlyHelperPackageAndCrossPackageTypes	Recording	#78428599291	Logs
✅	RunFromParentDirectory_UsesExistingConfigNearAppHost	Recording	#78428598982	Logs
✅	RunReportsSyntaxErrorsForDotNetAppHost	Recording	#78428599178	Logs
✅	RunReportsSyntaxErrorsForTypeScriptAppHost	Recording	#78428599178	Logs
✅	SecretCrudOnDotNetAppHost	Recording	#78428599280	Logs
✅	SecretCrudOnTypeScriptAppHost	Recording	#78428598903	Logs
✅	StagingChannel_ConfigureAndVerifySettings_ThenSwitchChannels	Recording	#78428599170	Logs
✅	StartAndWaitForTypeScriptSqlServerAppHostWithNativeAssets	Recording	#78428599351	Logs
✅	StartReportsSyntaxErrorsForDotNetAppHost	Recording	#78428599178	Logs
✅	StartReportsSyntaxErrorsForTypeScriptAppHost	Recording	#78428599178	Logs
✅	StopAllAppHostsFromAppHostDirectory	Recording	#78428598852	Logs
✅	StopJavaPolyglotAppHostUsingApphostDirectory	Recording	#78428599454	Logs
✅	StopNonInteractiveSingleAppHost	Recording	#78428598852	Logs
✅	StopTypeScriptPolyglotAppHostUsingApphostDirectory	Recording	#78428599029	Logs
✅	StopWithNoRunningAppHostExitsSuccessfully	Recording	#78428599143	Logs
✅	UnAwaitedChainsCompileWithAutoResolvePromises	Recording	#78428599284	Logs
❔	UpdateProjectChannelToStable_CSharpEmptyAppHost_PreservesAspireConfigChannel	Recording	#78428599073	Logs
✅	UpdateProjectChannelToStable_CSharpSingleFileInit_PreservesAspireConfigChannel	Recording	#78428599073	Logs
✅	UpdateProjectChannelToStable_TypeScriptSingleFileInit_PreservesAspireConfigChannel	Recording	#78428599073	Logs
✅	UpdateProjectChannelToStable_TypeScript_PreviewsStablePackagesAndPreservesChannel	Recording	#78428599073	Logs

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