Azure-functions-host: Using latest .NET Core 3.0 packages with Azure Functions v2 (like System.Text.Encodings.Web) causes "Method not found" issue due to assembly version mismatch

[ahsonkhan]

Is your question related to a specific version? If so, please specify:

Azure Functions v2

What language does your question apply to? (e.g. C#, JavaScript, Java, All)

C#

Question

From https://github.com/dotnet/corefx/issues/41534 (System.Text.Json: Method not found System.Text.Encodings.Web.TextEncoder.FindFirstCharacterToEncodeUtf8)

Works perfectly well in every project _except_ Azure Functions (v2).
Simply HTTP trigger an Azure Function and try and serialize (or deserialize) an object.

cc @electricessence, @fabiocav

Is there a workaround to this dependency version pinning issue?

This issue looks similar to https://github.com/Azure/azure-functions-host/issues/4906.

Here's a repro with a similar error:

System.Private.CoreLib: Exception while executing function: Function1. TestDependency: Method not found: 'System.Text.Encodings.Web.JavaScriptEncoder System.Text.Encodings.Web.JavaScriptEncoder.get_UnsafeRelaxedJsonEscaping()'.

```csproj


netcoreapp2.1
v2







PreserveNewest


PreserveNewest
Never

```C#
public static class Function1
{
    [FunctionName("Function1")]
    public static async Task<IActionResult> Run(
        [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpRequest req,
        ILogger log)
    {
        log.LogInformation("C# HTTP trigger function processed a request.");

        string name = req.Query["name"];

        string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
        dynamic data = JsonConvert.DeserializeObject(requestBody);

        var output = new MemoryStream();
        using (var writer = new Utf8JsonWriter(output, 
            new JsonWriterOptions { Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping }))
        {
            writer.WriteString(Encoding.UTF8.GetBytes("name"), "Bob1");
            writer.Flush();
        }

        name = System.Text.Json.JsonSerializer.Serialize(Encoding.UTF8.GetString(output.ToArray()));

        return name != null
            ? (ActionResult)new OkObjectResult($"Hello, {name}")
            : new BadRequestObjectResult("Please pass a name on the query string or in the request body");
    }
}

Http Functions:

        Function1: [GET,POST] http://localhost:7071/api/Function1

[10/7/2019 3:09:01 AM] Host lock lease acquired by instance ID '000000000000000000000000B068BFBB'.
[10/7/2019 3:09:07 AM] Executing HTTP request: {
[10/7/2019 3:09:07 AM]   "requestId": "a37a95c1-868d-484d-82d9-f9cc6e34ba3b",
[10/7/2019 3:09:07 AM]   "method": "GET",
[10/7/2019 3:09:07 AM]   "uri": "/api/Function1"
[10/7/2019 3:09:07 AM] }
[10/7/2019 3:09:07 AM] Executing 'Function1' (Reason='This function was programmatically called via the host APIs.', Id=c9432a44-ea43-4ad9-b45a-7b642c43f07c)
[10/7/2019 3:09:08 AM] Executed 'Function1' (Failed, Id=c9432a44-ea43-4ad9-b45a-7b642c43f07c)
[10/7/2019 3:09:08 AM] System.Private.CoreLib: Exception while executing function: Function1. TestDependency: Method not found: 'System.Text.Encodings.Web.JavaScriptEncoder System.Text.Encodings.Web.JavaScriptEncoder.get_UnsafeRelaxedJsonEscaping()'.
[10/7/2019 3:09:09 AM] Executed HTTP request: {
[10/7/2019 3:09:09 AM]   "requestId": "a37a95c1-868d-484d-82d9-f9cc6e34ba3b",
[10/7/2019 3:09:09 AM]   "method": "GET",
[10/7/2019 3:09:09 AM]   "uri": "/api/Function1",
[10/7/2019 3:09:09 AM]   "identities": [
[10/7/2019 3:09:09 AM]     {
[10/7/2019 3:09:09 AM]       "type": "WebJobsAuthLevel",
[10/7/2019 3:09:09 AM]       "level": "Admin"
[10/7/2019 3:09:09 AM]     }
[10/7/2019 3:09:09 AM]   ],
[10/7/2019 3:09:09 AM]   "status": 500,
[10/7/2019 3:09:09 AM]   "duration": 2444
[10/7/2019 3:09:09 AM] }

Looks like the .NET Core 2.2 dependencies are overriding the newer ones that the user code might bring in/rely on:
https://github.com/Azure/azure-functions-host/blob/a63aeed826c4a1ee7c4e8c676bf7557c88a86ba1/src/WebJobs.Script.WebHost/WebJobs.Script.WebHost.csproj#L53-L66

For example: Microsoft.AspNetCore.App version 2.2.7 brings in the version 4.0.3.0 of the assembly where-as the version that S.T.Json depends on is 4.0.4.0 (this is the version that ships in-box with .NET Core 3.0 and is available as part of the latest 4.6.0 NuGet package).

The function output directory has the right dlls:

However, Azure Functions is loading the older dll first (that comes built-in with the azure functions cli):

[espray]

Azure/app-service-announcements#200

[electricessence]

Thanks for looking into this. Is there any work around for S.T.J. currently? Migrating to Azure Fn v3 is an option, but we are currently blocked by this issue.

[espray]

Az Host pins versions of specific assemblies and will always lag behind latest releases by some amount. 2.2 is what compatible with Function Runtime Version: 2.0.12673.0

Self host in a container is always an option.

[electricessence]

@espray I can't even get this to work locally on my dev machine? How might I proceed?
Is there some assembly hack I can put in to reference the proper STEW package version?

[espray]

I think your only option for core 3 right now, build v3.x branch and host it container. No clue how stable v3.x branch is.

[fabiocav]

We'll have a preview (with a supporting version of the CLI) available very soon. Please keep an eye on the announcement @espray linked above as we'll update it once those bits become available.

[electricessence]

@fabiocav thanks for the update. Do you have an 'earliest' vs 'latest' timeframe?

[espray]

Next Azure Functions Live is scheduled for the 10th
https://www.youtube.com/watch?v=E_xcnwNONZc

[ahsonkhan]

cc @terrajobst

[electricessence]

:( (sigh) Live rescheduled for the 22nd.

[dtate22]

On 10/15/2019 @ 5:54 pm - I spent 2 hours trying everything in this thread.

• I tried the simplest solutions including just switching my versions of Microsoft.NetCore
• I also attempted to use different methods to parse
• Because I'm on a timeline, I had to drop back and punt because my code has to be production ready and I cannot afford to take too many chances and break my release cycle

The System.Text.Json is just not mature enough yet

• I had to drop back from
  OpportunityChangesLastXMins oBody = JsonSerializer.Deserialize(sJSON);

• To:
  OpportunityChangesLastXMins oBody = JsonConvert.DeserializeObject(sJSON);

I tried almost everything in this chain.

Also, I will say this, I'm using Azure functions to code my solution and the code ONLY breaks in the Visual Studio Azure functions testing harness.

I broke my code out in a .NetCore Console App and it worked perfectly using System.Text.Json.

So, it might be something in one of my many runtimes.

[dtate22]

Thanks to the guys at the following blog, they helped me confirm my issue:
@ahsonkhan
@pranavkm
@markgr

https://github.com/aspnet/AspNetCore/issues/13093

[dtate22]

@ahsonkhan - Hey man, thanks for the information... (Thanks for the information - I will go to the URL listed above)

• It's crazy how many different places you have to look to solve a problem.

@pranavkm - I used the following tested versions before posting to the blog. I didn't want to mis-lead people because I hadn't done my research

• .netCore 2.0 - failed (nuget System.Text.Json version)
• .netCore 2.1 - failed (nuget System.Text.Json version)
• .netCore 2.2 - failed (nuget System.Text.Json version)
• .netCore 3.0 - failed (for this version, I had to uninstall the packages because the JSON is native)
• .netCore 3.1 - failed - would not compile my Azure Function

@markgr - Thanks for the commands - here's my dump
dotnet --list-sdks
2.1.602 [C:\Program Files\dotnet\sdk]
2.1.700 [C:\Program Files\dotnet\sdk]
2.1.801 [C:\Program Files\dotnet\sdk]
3.0.100 [C:\Program Files\dotnet\sdk]
3.1.100-preview1-014459 [C:\Program Files\dotnet\sdk]

dotnet --list-runtimes
Microsoft.AspNetCore.All 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.1.11 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.1.12 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.1.9 [C:\Program Files\dotnet\sharedMicrosoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.1.11 [C:\Program Files\dotnet\sharedMicrosoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.1.12 [C:\Program Files\dotnet\sharedMicrosoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.1.13 [C:\Program Files\dotnet\sharedMicrosoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.0.0 [C:\Program Files\dotnet\sharedMicrosoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.0-preview1.19508.20 [C:\Program Files\dotnet\sharedMicrosoft.AspNetCore.App]
Microsoft.NETCore.App 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.1.11 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.1.12 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.0.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.0-preview1.19506.1 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 3.0.0 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 3.1.0-preview1.19506.1 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

You guys are great - thanks for helping me out by posting the information above - appreciate it!

Later

[electricessence]

@dtate22 Are you suggesting you solved this problem? I was under the impression it was not solvable (pinned reference) and that all I could do was wait till (~10/25) for the new AFv3 to come out.

[espray]

@electricessence 10/25 is the next comunity update. Last update on AzFunc core 3 estimated 2020 q1 was ga

[ashrafsabrym]

I had this very same issue with my Blazor app.
Changing the TargetFramework of my Blazor client app and shared library projects from netstandard2.1 to netstandard2.0 resolved the issue.