Az.Resources: AzDeployment cmdlets emit an empty WARNING line

[yaegashi]

Description

The AzDeployment cmdlets (including New-AzSubscriptionDeployment, Test-AzSubscriptionDeployment, etc.) consistently emit an unexpected empty WARNING line to the console when using any Bicep input files that do not contain any errors or warnings.

PS> Set-Content -Path hello.bicep -Value "output hello string = 'hello'"
PS> Test-AzSubscriptionDeployment -Location japaneast -TemplateFile ./hello.bicep         
WARNING: 

PS> Test-AzSubscriptionDeployment -Verbose -Location japaneast -TemplateFile ./hello.bicep
VERBOSE: Using Bicep v0.25.3
VERBOSE: Calling Bicep with arguments: build "/workspaces/dxcloud-iac/hello.bicep" --stdout
WARNING: 

VERBOSE: 1:04:35 PM - Template is valid.

The Bicep process does not output any errors or warnings to stderr.

PS> bicep build ./hello.bicep --stdout >stdout 2>stderr
PS> ls -l std*
-rw-rw-rw- 1 vscode vscode   0 Feb 12 13:10 stderr
-rw-rw-rw- 1 vscode vscode 384 Feb 12 13:10 stdout

No WARNING lines should be expected when valid Bicep inputs without any errors or warnings are used.

Issue script & Debug output

PS> $DebugPreference = 'Continue'
PS> Set-Content -Path hello.bicep -Value "output hello string = 'hello'"                  
PS> Test-AzSubscriptionDeployment -Verbose -Location japaneast -TemplateFile ./hello.bicep
VERBOSE: Using Bicep v0.25.3
VERBOSE: Calling Bicep with arguments: build "/workspaces/dxcloud-iac/hello.bicep" --stdout
WARNING: 

DEBUG: 12:45:16 PM - TestAzureSubscriptionDeploymentCmdlet begin processing with ParameterSet 'ByTemplateFileWithNoParameters'.
DEBUG: 12:45:16 PM - using account id 'azure-cli'...
DEBUG: 12:45:16 PM - [ConfigManager] Got nothing from [DisplayBreakingChangeWarning], Module = [], Cmdlet = []. Returning default value [True].
DEBUG: ============================ HTTP REQUEST ============================

HTTP Method:
POST

Absolute Uri:
https://management.azure.com/subscriptions/57e3d747-fe92-4334-bb7a-9648d518adeb/providers/Microsoft.Resources/deployments/6c885142-9cd0-48bf-81c5-47dfb71d61ce/validate?api-version=2022-09-01

Headers:
Accept-Language               : en-US
x-ms-client-request-id        : abc5e568-d735-49a0-aecc-d2b7b2c38e38

Body:
{
  "location": "japaneast",
  "properties": {
    "template": {
      "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
      "resources": [],
      "contentVersion": "1.0.0.0",
      "metadata": {
        "_generator": {
          "name": "bicep",
          "version": "0.25.3.34343",
          "templateHash": "16951429577663310116"
        }
      },
      "outputs": {
        "hello": {
          "type": "string",
          "value": "hello"
        }
      }
    },
    "parameters": {},
    "mode": "Incremental"
  }
}


DEBUG: ============================ HTTP RESPONSE ============================

Status Code:
OK

Headers:
Cache-Control                 : no-cache
Pragma                        : no-cache
x-ms-ratelimit-remaining-subscription-writes: 1199
x-ms-request-id               : 8ebed6bd-b119-473d-9b41-469a5869b0d9
x-ms-correlation-request-id   : 8ebed6bd-b119-473d-9b41-469a5869b0d9
x-ms-routing-request-id       : SOUTHEASTASIA:20240212T124517Z:8ebed6bd-b119-473d-9b41-469a5869b0d9
Strict-Transport-Security     : max-age=31536000; includeSubDomains
X-Content-Type-Options        : nosniff
X-Cache                       : CONFIG_NOCACHE
X-MSEdge-Ref                  : Ref A: 0EE895BE5C434162A2BD02FA6EBDBC7F Ref B: MAA201060513011 Ref C: 2024-02-12T12:45:17Z
Date                          : Mon, 12 Feb 2024 12:45:16 GMT

Body:
{
  "id": "/subscriptions/57e3d747-fe92-4334-bb7a-9648d518adeb/providers/Microsoft.Resources/deployments/6c885142-9cd0-48bf-81c5-47dfb71d61ce",
  "name": "6c885142-9cd0-48bf-81c5-47dfb71d61ce",
  "type": "Microsoft.Resources/deployments",
  "location": "japaneast",
  "properties": {
    "templateHash": "16951429577663310116",
    "mode": "Incremental",
    "provisioningState": "Succeeded",
    "timestamp": "0001-01-01T00:00:00Z",
    "duration": "PT0S",
    "correlationId": "8ebed6bd-b119-473d-9b41-469a5869b0d9",
    "providers": [],
    "dependencies": [],
    "validatedResources": []
  }
}


VERBOSE: 12:45:17 PM - Template is valid.
DEBUG: 12:45:17 PM - [ConfigManager] Got nothing from [DisplayRegionIdentified], Module = [], Cmdlet = []. Returning default value [True].
DEBUG: 12:45:17 PM - [ConfigManager] Got nothing from [CheckForUpgrade], Module = [], Cmdlet = []. Returning default value [True].
DEBUG: AzureQoSEvent:  Module: Az.Resources:6.15.1; CommandName: Test-AzDeployment; PSVersion: 7.4.1; IsSuccess: True; Duration: 00:00:00.5831028
DEBUG: 12:45:17 PM - [ConfigManager] Got nothing from [EnableDataCollection], Module = [], Cmdlet = []. Returning default value [True].
DEBUG: 12:45:17 PM - TestAzureSubscriptionDeploymentCmdlet end processing.

Environment data

PS> $PSVersionTable              

Name                           Value
----                           -----
PSVersion                      7.4.1
PSEdition                      Core
GitCommitId                    7.4.1
OS                             Ubuntu 22.04.3 LTS
Platform                       Unix
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

Module versions

PS> Get-Module Az*          

ModuleType Version    PreRelease Name                                ExportedCommands
---------- -------    ---------- ----                                ----------------
Script     2.15.1                Az.Accounts                         {Add-AzEnvironment, Clear-AzConfig, Clear-AzContext, Clear-AzDefault…}
Script     7.1.1                 Az.Compute                          {Add-AzImageDataDisk, Add-AzVhd, Add-AzVMAdditionalUnattendContent, Add-AzVMDataDisk…}
Script     4.3.0                 Az.DesktopVirtualization            {Disconnect-AzWvdUserSession, Expand-AzWvdMsixImage, Get-AzWvdApplication, Get-AzWvdApplicationGroup…}
Script     0.4.0                 Az.ImageBuilder                     {Get-AzImageBuilderTemplate, Get-AzImageBuilderTemplateRunOutput, Get-AzImageBuilderTrigger, New-AzImageBuilderTempl…
Script     5.2.0                 Az.KeyVault                         {Add-AzKeyVaultCertificate, Add-AzKeyVaultCertificateContact, Add-AzKeyVaultKey, Add-AzKeyVaultManagedStorageAccount…
Script     7.4.0                 Az.Network                          {Add-AzApplicationGatewayAuthenticationCertificate, Add-AzApplicationGatewayBackendAddressPool, Add-AzApplicationGat…
Script     6.15.1                Az.Resources                        {Export-AzResourceGroup, Export-AzTemplateSpec, Get-AzDenyAssignment, Get-AzDeployment…}

Error output

No response

[yaegashi]

The suspicious part in BicepUtility.cs:

https://github.com/Azure/azure-powershell/blob/52f9aad305752fc419c6013b10f9127c243f34d4/src/Resources/ResourceManager/Utilities/BicepUtility.cs#L214-L218

[isra-fel]

Thanks for the feedback. Let me loop in deployment team. One possibility is that output.Stderr contained whitespace characters.

[microsoft-github-policy-service[bot]]

Thanks for the feedback! We are routing this to the appropriate team for follow-up. cc @Azure/deployments-owners.

[microsoft-github-policy-service[bot]]

Thanks for the feedback! We are routing this to the appropriate team for follow-up. cc @Azure/deployments-owners.

[DCMattyG]

I'm seeing the same thing. Thank goodness I came across this issue because I thought I was going crazy!