'In process' hosting model breaks running Angular SPAs from Visual Studio

[kccsf]

Describe the bug

Setting hosting model to 'In process' causes Angular SPAs to break when running from Visual Studio in both debug and release modes.

To Reproduce

Using:
Visual Studio Community 2017 Preview - 15.9.0 Preview 5.0
AspNetCore: 2.2.0-preview3-35497
node: 9.4.0
npm: 6.4.1

Steps:
File -> New project -> ASP.NET Core Web Application -> Angular
Runs fine.

Open project settings -> Debug, set hosting model to 'In Process'. Subsequent run then gives an aggregate error. The (hopefully!) pertinent part:

[2] See the InnerException for further details of the cause. ---> System.ComponentModel.Win32Exception: The directory name is invalid
at System.Diagnostics.Process.StartWithCreateProcess(ProcessStartInfo startInfo)
at System.Diagnostics.Process.Start()
at System.Diagnostics.Process.Start(ProcessStartInfo startInfo)
at Microsoft.AspNetCore.NodeServices.Npm.NpmScriptRunner.LaunchNodeProcess(ProcessStartInfo startInfo)
--- End of inner exception stack trace ---
at Microsoft.AspNetCore.NodeServices.Npm.NpmScriptRunner.LaunchNodeProcess(ProcessStartInfo startInfo)
at Microsoft.AspNetCore.NodeServices.Npm.NpmScriptRunner..ctor(String workingDirectory, String scriptName, String arguments, IDictionary2 envVars) at Microsoft.AspNetCore.SpaServices.AngularCli.AngularCliMiddleware.StartAngularCliServerAsync(String sourcePath, String npmScriptName, ILogger logger) --- End of inner exception stack trace --- at System.Threading.Tasks.Task1.GetResultCore(Boolean waitCompletionNotification)
at Microsoft.AspNetCore.SpaServices.AngularCli.AngularCliMiddleware.<>c.b__2_0(Task1 task) at System.Threading.Tasks.ContinuationResultTaskFromResultTask2.InnerInvoke()
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location where exception was thrown ---
at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot)
--- End of inner exception stack trace ---
at System.Threading.Tasks.Task1.GetResultCore(Boolean waitCompletionNotification) at Microsoft.AspNetCore.SpaServices.Extensions.Util.TaskTimeoutExtensions.WithTimeout[T](Task1 task, TimeSpan timeoutDelay, String message)
at Microsoft.AspNetCore.SpaServices.Extensions.Proxy.SpaProxy.PerformProxyRequest(HttpContext context, HttpClient httpClient, Task`1 baseUriTask, CancellationToken applicationStoppingToken, Boolean proxy404s)
at Microsoft.AspNetCore.Builder.SpaProxyingExtensions.<>c__DisplayClass2_0.<b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at Microsoft.AspNetCore.Routing.EndpointMiddleware.Invoke(HttpContext httpContext)
at Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware.Invoke(HttpContext httpContext)
at Microsoft.AspNetCore.StaticFiles.StaticFileMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)
---> (Inner Exception #0) System.AggregateException: One or more errors occurred. (Failed to start 'npm'. To resolve this:.

Expected behavior

Business as usual

Additional context

dotnet --info:
.NET Core SDK (reflecting any global.json):
Version: 2.2.100-preview3-009430
Commit: e0a11c9929

Runtime Environment:
OS Name: Windows
OS Version: 10.0.17134
OS Platform: Windows
RID: win10-x64
Base Path: C:\Program Files\dotnet\sdk\2.2.100-preview3-009430\

Host (useful for support):
Version: 2.2.0-preview3-27014-02
Commit: 525082ca3e

.NET Core SDKs installed:
2.1.202 [C:\Program Files\dotnet\sdk]
2.1.403 [C:\Program Files\dotnet\sdk]
2.1.500-preview-009335 [C:\Program Files\dotnet\sdk]
2.1.500-preview-009404 [C:\Program Files\dotnet\sdk]
2.2.100-preview3-009430 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed:
Microsoft.AspNetCore.All 2.1.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.2.0-preview3-35497 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.1.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.2.0-preview3-35497 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 2.0.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.1.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.2.0-preview3-27014-02 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]

[amattias]

I have just run into the same issue after upgrading to .Net Core 2.2.0

[arnvanhoutte]

I also have the same issue on IIS Express

[milendimo]

Same here, VS 2017 Enterprise 15.9.4.

All works fine in VS Code.

[jkotalik]

Same issue as #4206. See https://github.com/aspnet/Docs/blob/master/aspnetcore/host-and-deploy/aspnet-core-module/samples_snapshot/2.x/CurrentDirectoryHelpers.cs for our recommended work around. This behavior will be eventually patched.

Closing for now, please reopen if you still have the same issue, or a separate issue if you are experiencing different issues.