cli errors do not go to stderror stream

[esmadau]

swashbuckle version: 6.1.4 and 6.4.0

In a case where .NET version expected to be able to use dotnet swagger is not found, the output seems like it should be an error, but instead is just informational. This is causing issues when trying to use this in processes where an error is expected to fail the task appropriately, whether the failure occurs on writing the file or anything else around using dotnet swagger.
This seems to be a general issue, not relating to a specific version of the cli.

Repro:

• ensure 'Microsoft.AspNetCore.App', version '5.0.0' is not installed
• use swashbuckle version 6.1.4
• ensure $ErrorActionPreference is set to default of Continue when running in Powershell
• use dotnet swagger in try catch, see that error does not occur. Ex: try{dotnet swagger}catch{Write-Host "error occurred."}

Example:

PS C:\dev\> try{dotnet swagger}catch{Write-Host "error occurred."}
You must install or update .NET to run this application.

App: C:\Users\x\.nuget\packages\swashbuckle.aspnetcore.cli\6.1.4\tools\net5.0\any\dotnet-swagger.dll
Architecture: x64
Framework: 'Microsoft.AspNetCore.App', version '5.0.0' (x64)
.NET location: C:\Program Files\dotnet\

The following frameworks were found:
  6.0.7 at [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]

Learn about framework resolution:
https://aka.ms/dotnet/app-launch-failed

To install missing framework, download:
https://aka.ms/dotnet-core-applaunch?framework=Microsoft.AspNetCore.App&framework_version=5.0.0&arch=x64&rid=win10-x64
PS C:\dev\>

Repro:

• use swashbuckle version 6.4.0
• ensure $ErrorActionPreference is set to default of Continue when running in Powershell
• use dotnet swagger in try catch with a wrong path to assembly, see that error does not occur. Ex: try{dotnet swagger tofile --output unknown src\unknown.dll v1}catch{Write-Host "error occured."

An error is also not thrown when the assembly provided is not found:

PS C:\dev\> try{dotnet swagger tofile --output unknown src\unknown.dll v1}catch{Write-Host "error occured."}
Unhandled exception. System.IO.FileNotFoundException: src\unknown.dll
   at Swashbuckle.AspNetCore.Cli.Program.<>c__DisplayClass0_0.<Main>b__2(IDictionary`2 namedArgs) in C:\projects\ahoy\src\Swashbuckle.AspNetCore.Cli\Program.cs:line 41
   at Swashbuckle.AspNetCore.Cli.CommandRunner.Run(IEnumerable`1 args) in C:\projects\ahoy\src\Swashbuckle.AspNetCore.Cli\CommandRunner.cs:line 68
   at Swashbuckle.AspNetCore.Cli.CommandRunner.Run(IEnumerable`1 args) in C:\projects\ahoy\src\Swashbuckle.AspNetCore.Cli\CommandRunner.cs:line 59
   at Swashbuckle.AspNetCore.Cli.Program.Main(String[] args) in C:\projects\ahoy\src\Swashbuckle.AspNetCore.Cli\Program.cs:line 121

[esmadau]

Is this related to dotnet cli in general streaming everything to stdout? dotnet/sdk#7289 (comment)

[github-actions]

This issue is stale because it has been open for 60 days with no activity. It will be automatically closed in 14 days if no further updates are made.

[martincostello]

Yep, this is an issue with .NET rather than us. Our code doesn't get executed in this scenario.