The type or namespace name 'Google' could not be found

[Agredek]

Project won't build under Linux on Unity 6.x.

Description of the bug
Livekit assembly cannot be built because of missing references.

The Google.Protobuf.dll is in the package, but it seems to be targeting only Windows devices.

How to reproduce
Pull client-sdk-unity to any project using Unity's Package Manager while on Linux OS. In my case it's Ubuntu but I've tried other distros with the same result.

Tested on

• Ubuntu 24.04
• Ubuntu 24.10
• Debian 13.3.0
• Unity 6000.2.6f2

[Agredek]

Here's the fastest solution I've come up with:

• Install dotnet-sdk-8.0. You'll need this version for Google.Protobuf.
  sudo apt install dotnet-sdk-8.0
• Create a new directory for a dotnet project
  mkdir protobuf-3.22
• Create a new dotnet class library project
  dotnet new classlib -n GoogleProtobuf322
• Move to newly-created dir
  cd GoogleProtobuf322/
• Set target framework for the project
  sed -i 's|<TargetFramework>.*</TargetFramework>|<TargetFramework>netstandard2.0</TargetFramework>|' GoogleProtobuf322.csproj
• Set language version of the project to 8.0
  sed -i '/<PropertyGroup>/a\ \ \ \ <LangVersion>8.0</LangVersion>' GoogleProtobuf322.csproj
• Add Google.Protobuf package version 3.22.0
  dotnet add package Google.Protobuf --version 3.22.0
• Restore and build the project
  dotnet restore dotnet build -c Release
• You should be able to find a new Google.Protobuf.dll in you bin directory.
• If it's missing find the location of the dll in your nuget cache
  find ~/.nuget/packages/google.protobuf/3.22.0/ -type f -name "Google.Protobuf.dll" -print
  and copy it to your project
  cp ~/.nuget/packages/google.protobuf/3.22.0/lib/netstandard2.0/Google.Protobuf.dll .
  "." will use current dir.

Now you can replace Livekit's Google.Protobuf.dll with your own which will be targeting both Windows and Linux devices. I've attached working version to this comment.
Google.Protobuf.zip