Referencing Template Specs is broken in versions 0.6.1 and 0.6.11

[pb111111]

Bicep version
Bicep CLI version 0.6.11 (cecfb5c)

Describe the bug
With the latest version of the bicep CLI, I am unable to reference Template Spec modules. If I inspect the cached copy of the module in main.json, the mainTemplate object appears empty:

Version 0.6.11 and Version 0.6.1

❯ cat [cache-path]\[rg-name]\[tsname]\1.0.3\main.json
{
  "id": "/subscriptions/[subscription]/resourceGroups/[rg]/providers/Microsoft.Resources/templateSpecs/[tsname]/versions/1.0.3",
  "name": "1.0.3",
  "type": "Microsoft.Resources/templateSpecs/versions",
  "location": "eastus2",
  "tags": {},
  "systemData": {},
  "properties": {
    "linkedTemplates": [],
    "mainTemplate": {}
  }
}

Version 0.5.6

{
  "id": "/subscriptions/[subscription]/resourceGroups/[rg]/providers/Microsoft.Resources/templateSpecs/[tsname]/versions/1.0.3",
  "name": "1.0.3",
  "type": "Microsoft.Resources/templateSpecs/versions",
  "location": "eastus2",
  "tags": {},
  "systemData": {},
  "properties": {
    "linkedTemplates": [],
    "mainTemplate": {
      "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
      "contentVersion": "1.0.0.0",
      "metadata": {
        "_generator": {
          "name": "bicep",
          "version": "0.6.11.53198",
          "templateHash": "13169941131891395286"
        }
      },
      "parameters": {
        "roleNames": {
          "type": "array",
          "allowedValues": [
            // omitted
          ]
        },
        "principalId": {
          "type": "string"
        },
        "principalType": {
          "type": "string",
          "allowedValues": [
            "User",
            "Group",
            "ServicePrincipal"
          ]
        }
      },
      "variables": {
        "builtInRoles": {
         // omitted
        }
      },
      "resources": [
        {
          "copy": {
            "name": "roleAssignments",
            "count": "[length(parameters('roleNames'))]"
          },
          "type": "Microsoft.Authorization/roleAssignments",
          "apiVersion": "2020-04-01-preview",
          "name": "[guid(resourceGroup().id, parameters('roleNames')[copyIndex()], parameters('principalId'))]",
          "properties": {
            "roleDefinitionId": "[subscriptionResourceId('Microsoft.Authorization/roleDefinitions', variables('builtInRoles')[parameters('roleNames')[copyIndex()]])]",
            "principalId": "[parameters('principalId')]",
            "principalType": "[parameters('principalType')]"
          }
        }
      ]
    }
  }
}

In version 0.5.6, the error message does not appear.
In version 0.6.11 and 0.6.1, the error message appears as:

❯ bicep build .\db.bicep
C:\path\file.bicep(78,60) : Error BCP104: The referenced module has errors.
C:\path\file.bicep(82,5) : Error BCP037: The property "roleNames" is not allowed on objects of type "params". No other properties are allowed.
C:\path\file.bicep(85,5) : Error BCP037: The property "principalId" is not allowed on objects of type "params". No other properties are allowed.
C:\path\file.bicep(86,5) : Error BCP037: The property "principalType" is not allowed on objects of type "params". No other properties are allowed.

To Reproduce

• Reference a template spec in your bicep file with the latest version of the CLI.

module symbolicName 'ts/MySpecs:Name:1.0.3' = {
  scope: resourceGroup()
  name: 'deployment123'
  params: {
    roleNames: [
      'Contributor'
    ]
    principalId: userAssignedIdentity.properties.principalId
    principalType: 'ServicePrincipal'
  }
}

Additional context
Add any other context about the problem here.

[MichielCornilleKenze]

Can confirm. I can reproduce this with 0.6.11

[shenglol]

Might be due to bumping Azure.ResourceManager.Resources to 1.0 (#6538) but needs further investigation to confirm.

[shenglol]

Confirmed that it's due to a breaking change in the Azure.ResourceManager.Resources package. I'm working on a fix now.

[pb111111]

@shenglol I just verified this build, 0.6.18 (36324f8), fixes my issue.

[bhsubra]

This issue should be fixed with today's 0.6.18 release. Let us know if there are any concerns. Thanks!