FileNotFoundException: Could not load file or assembly for Function app referencing custom assembly

I'm running Host from the latest sources of `dev` branch as described in [Running locally (Visual Studio) (v2+)](https://github.com/Azure/azure-functions-host/blob/dev/CONTRIBUTING.md#running-locally-visual-studio-v2).

I'm pointing to my test Function App which consists of two C# projects: `FunctionApp` and it references a library `Lib`. When I start debugging and call the function, I get

> FileNotFoundException: Could not load file or assembly 'Lib...


If I remove the reference of library and all usages, the functions runs just fine.

It seems to be a recent regression, since the exact same project works fine when I checkout `v2.0.11651-alpha`. `v2.0.11737-alpha` already fails.

Function App is referencing `Microsoft.NET.Sdk.Functions` version `1.0.13`, and is just a basic app with 1 HTTP function.