This repo aims to reproduce issue https://github.com/dotnet/efcore/issues/19759

Instructions

1. Open the solution file in Visual Studio 2019
2. Open Package Manager Console window
3. Type the following command:

Add-Migration abc -Project EfCoreMigrationLinuxBug.Data -StartupProject EfCoreMigrationLinuxBug

Result

This file is created on disk:

Migrations\20200216202455_abc.Designer.cs

This entry is added to EfCoreMigrationLinuxBug.Data.csproj:

<Compile Include="Migrations\20200216202455_abc.designer.cs" />

Notice the difference between "Designer" and "designer", which introduces a build error on Linux.

Comment

These entries does not normally turn up in the csproj. The behaviour was activated by these lines that I (mysteriously) had in the csproj:

<ItemGroup>
    <Compile Remove="Migrations\**" />
    <EmbeddedResource Remove="Migrations\**" />
    <None Remove="Migrations\**" />
</ItemGroup>