Distribute Linux Binaries for .NET Core on NuGet

[mattleibow]

For most users of the common linux distros (Ubuntu, Debian, Red Hat, OpenSUSE, etc) it may be possible to distribute a binary in the NuGet package.

There are some limitations and reason why this is not such a good idea, but this is just an issue to track this thought.

Just want to link the main, but old, linux issue: #90

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To make life easier for everyone, I moved code around and added a new target to the GN files. Now, the native libSkiaSharp build is done with GN and ninja directly: https://github.com/mono/SkiaSharp/wiki/Building-on-Linux

[kekekeks]

For people looking for prebuilt binaries: there is a prebuilt nuget package maintained by AvaloniaUI team. Despite the name it only contains libSkiaSharp.so. For docker images provided by microsoft you need to install libfontconfig1 package via apt-get.

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Regarding providing prebuilt binaries in official package:

Please, link libstdc++ statically and use something with sufficiently old GLIBC as your build machine. This will allow to produce a single binary for almost every modern distro.

Ubuntu 14.04 is a good candidate for that since it has GLIBC 2.19 and modern compiler toolchain available from official repositories

[andrii-litvinov]

@kekekeks, I am trying to use this package with .NET Core 2.0 in linux in a container based on https://hub.docker.com/r/microsoft/aspnetcore/ and get runtime exception

System.TypeInitializationException: The type initializer for 'SkiaSharp.SKImageInfo' threw an exception. ---> System.DllNotFoundException: Unable to load DLL 'libSkiaSharp': The specified module or one of its dependencies could not be found.

though I can see the file in the output folder runtimes\linux-x64\native\libSkiaSharp.so . I am new to linux and not sure where to look for a solution. Do you know what I might be doing wrong? Or do you have any manual on how to use it? I have only installed the package.

[kekekeks]

Try to use self-contained deployment, something like:

dotnet restore -r debian.8-x64
dotnet publish -r debian.8-x64 -o publish-dir

It should properly pack all dependencies for you.

You can also use microsoft/dotnet:2.0-runtime-deps-jessie as your base docker image in that case.

[andrii-litvinov]

@kekekeks thank you for your response! I have tried different docker packages and different runtime configurations like debian.8-x64 and linux-x64. I can see libSkiaSharp.so in startup folder, but still get same exception. Probably I should wait for official support on Linux.

[kekekeks]

Check if you have all dependencies in your docker image. You can find them using lddtree libSkiaSharp.so. You image probably doesn't have libfontconfig1 package installed.

You can also try /lib/ld-linux.so.2 --verify ./libSkiaSharp.so or this simple utility to check for loader errors.

[andrii-litvinov]

@kekekeks I run ldd libSkiaSharp.so because it looks like that my image does not have lddtree. And it indeed says that it cannot find it: libfontconfig.so.1 => not found.

[andrii-litvinov]

I have done RUN apt-get update && apt-get install -y libfontconfig1 in my Dockerfile and and it worked 😄, thanks for the hints!

[Myszax]

Isn't https://www.nuget.org/packages/Avalonia.Skia.Linux.Natives/ outdated?

[kekekeks]

Do you need any particular feature of the recent SkiaSharp? It's kinda troublesome to build portable Linux binaries, so we avoid updating it unless it's really required.

[Myszax]

No, it was just a question.
I've download libSkiaSharp.so from 1.59.2 release and it works,
Anyway I am working on mono, still need to migrate to .NET Core.

[DanWBR]

What about a native library for Raspberry Pi (Raspbian)? Any news on the Linux ARM front?