System.IO.FileLoadException: Undefined resource string ID:0x80131621

[Zhiyuan-Amos]

Description

Observe that client.GetAsync errors out with the following error message: System.IO.FileLoadException: Undefined resource string ID:0x80131621. This issue only occurs when both conditions are true:

1. Using a HttpClient created with a custom HttpClientHandler overriding SendAsync (even though the overriding method merely calls the base method and so it should technically be equivalent to not overriding the method).

2. Specifying <InternalsVisibleTo> in the .csproj file, where the Include property has a value with at least 1 / e.g. ../ProjectMoreThanOnePathAway.

Reproduction Steps

// Program.cs
var client = new HttpClient(new CustomHttpClientHandler());
await client.GetAsync("https://www.google.com");

class CustomHttpClientHandler : HttpClientHandler
{
    protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) 
        => base.SendAsync(request, cancellationToken);
}

// .csproj
<InternalsVisibleTo Include="../ProjectMoreThanOnePathAway" />

I've created a minimal codebase to reproduce this issue: https://github.com/Zhiyuan-Amos/FileNotFoundError

Expected behavior

HTTP Request completes successfully.

Actual behavior

Http Request errors out with System.IO.FileLoadException: Undefined resource string ID:0x80131621.

Regression?

This error did not occur in .NET 6.

Known Workarounds

Make the Program class public using a partial class declaration (see dn for Integration Tests).

Configuration

.NET Version: 8
OS & Architecture: MacOS M1, Linux x64

Other information

No response

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