Azure CLI allows you to upgrade the .NET version to 10 on a Linux Consumption Function App using the CLI when this is only supported in Flex.

### Describe the bug

Create a function app in Linux consumption – dot net 8

Run the cli command below

system [ ~ ]$ az functionapp config set --name FALinuxY1 --resource-group testSK --linux-fx-version "DOTNET-ISOLATED|10.0"

{

"acrUseManagedIdentityCreds": false,

"acrUserManagedIdentityId": null,

"alwaysOn": false,

"apiDefinition": null,

"apiManagementConfig": null,

"appCommandLine": "",

"appSettings": null,

"autoHealEnabled": false,

"autoHealRules": null,

"autoSwapSlotName": null,

"azureStorageAccounts": {},

"connectionStrings": null,

"cors": {

"allowedOrigins": [

https://portal.azure.com/

],

"supportCredentials": false

},

"defaultDocuments": [

"Default.htm",

"Default.html",

"Default.asp",

"index.htm",

"index.html",

"iisstart.htm",

"default.aspx",

"index.php"

],

"detailedErrorLoggingEnabled": false,

"documentRoot": null,

"elasticWebAppScaleLimit": null,

"experiments": {

"rampUpRules": []

},

"ftpsState": "FtpsOnly",

"functionAppScaleLimit": 200,

"functionsRuntimeScaleMonitoringEnabled": false,

"handlerMappings": null,

"healthCheckPath": null,

"http20Enabled": false,

"http20ProxyFlag": 0,

"httpLoggingEnabled": false,

"id": "/subscriptions/f8d67923-d196-4541-bce2-74e00ada71ce/resourceGroups/testSK/providers/Microsoft.Web/sites/FALinuxY1",

"ipSecurityRestrictions": [

{

"action": "Allow",

"description": "Allow all access",

"headers": null,

"ipAddress": "Any",

"name": "Allow all",

"priority": 2147483647,

"subnetMask": null,

"subnetTrafficTag": null,

"tag": null,

"vnetSubnetResourceId": null,

"vnetTrafficTag": null

}

],

"ipSecurityRestrictionsDefaultAction": null,

"javaContainer": null,

"javaContainerVersion": null,

"javaVersion": null,

"keyVaultReferenceIdentity": null,

"kind": null,

"limits": null,

"linuxFxVersion": "DOTNET-ISOLATED|10.0",

"loadBalancing": "LeastRequests",

"localMySqlEnabled": false,

"location": "Canada Central",

"logsDirectorySizeLimit": 35,

"machineKey": null,

"managedPipelineMode": "Integrated",

"managedServiceIdentityId": null,

"metadata": null,

"minTlsCipherSuite": null,

"minTlsVersion": "1.2",

"minimumElasticInstanceCount": 1,

"name": "FALinuxY1",

"netFrameworkVersion": "v10.0",

"nodeVersion": "",

"numberOfWorkers": 1,

"phpVersion": "",

"powerShellVersion": "",

"preWarmedInstanceCount": 0,

"publicNetworkAccess": "Enabled",

"publishingUsername": "REDACTED",

"push": null,

"pythonVersion": "",

"remoteDebuggingEnabled": false,

"remoteDebuggingVersion": "VS2022",

"requestTracingEnabled": false,

"requestTracingExpirationTime": null,

"resourceGroup": "testSK",

"scmIpSecurityRestrictions": [

{

"action": "Allow",

"description": "Allow all access",

"headers": null,

"ipAddress": "Any",

"name": "Allow all",

"priority": 2147483647,

"subnetMask": null,

"subnetTrafficTag": null,

"tag": null,

"vnetSubnetResourceId": null,

"vnetTrafficTag": null

}

],

"scmIpSecurityRestrictionsDefaultAction": null,

"scmIpSecurityRestrictionsUseMain": false,

"scmMinTlsVersion": "1.2",

"scmType": "None",

"tags": {

"SecurityControl": "Ignore",

"hidden-link: /app-insights-resource-id": "/subscriptions/f8d67923-d196-4541-bce2-74e00ada71ce/resourceGroups/testSK/providers/microsoft.insights/components/FALinuxY1"

},

"tracingOptions": null,

"type": "Microsoft.Web/sites",

"use32BitWorkerProcess": false,

"virtualApplications": [

{

"physicalPath": "site\\wwwroot",

"preloadEnabled": false,

"virtualDirectories": null,

"virtualPath": "/"

}

],

"vnetName": "",

"vnetPrivatePortsCount": 0,

"vnetRouteAllEnabled": false,

"webSocketsEnabled": false,

"websiteTimeZone": null,

"windowsFxVersion": null,

"xManagedServiceIdentityId": null

}

Dot net version will be upgraded in stack settings to 10 and app goes down

Ask/Suggestion
When we execute the CLI command to upgrade the .NET version to 10, it should return an error indicating that this version is not supported, as stated in the official documentation.

Ref: [Guide for running C# Azure Functions in an isolated worker process | Microsoft Learn](https://nam06.safelinks.protection.outlook.com/?url=https:%2f%2flearn.microsoft.com%2fen-us%2fazure%2fazure-functions%2fdotnet-isolated-process-guide?tabs%3Dihostapplicationbuilder%252Cwindows&data=05%7c02%7cShashank.Ranjan%40microsoft.com%7ce7d829d5299240dc51d808de33e3cdda%7c72f988bf86f141af91ab2d7cd011db47%7c1%7c0%7c639005250670186911%7cUnknown%7cTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7c0%7c%7c%7c&sdata=Vxd6Fsa4XzFvlLfjIZjlXT8CSTGOmQoN8jNafcF%2Bi8I%3D&reserved=0)

### Related command

az functionapp config set --name FALinuxY1 --resource-group testSK --linux-fx-version "DOTNET-ISOLATED|10.0"

### Errors

No Errors are returned

### Issue script & Debug output

N/A

### Expected behavior

Linux Consumption shouldn't allow .NET 10

### Environment Summary

N/A

### Additional context

Nothing