Feature request: support Linux ARM / ARM64

[m-brooks]

Environment data

dotnet --info output:
.NET Core SDK (reflecting any global.json):
Version: 2.2.101
Commit: 236713b0b7

Runtime Environment:
OS Name: raspbian
OS Version: 9
OS Platform: Linux
RID: linux-arm
Base Path: /home/pi/dotnet/sdk/2.2.101/

Host (useful for support):
Version: 2.2.0
Commit: 1249f08fed

.NET Core SDKs installed:
2.2.101 [/home/pi/dotnet/sdk]

.NET Core runtimes installed:
Microsoft.AspNetCore.All 2.2.0 [/home/pi/dotnet/shared/Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.2.0 [/home/pi/dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 2.2.0 [/home/pi/dotnet/shared/Microsoft.NETCore.App]

VS Code version:
Version: 1.29.0 (user setup)
Commit: f74c7914490b68b4052ff877f04b6eaf7198f261
Date: 2018-10-16T15:00:48.287Z
Electron: 2.0.11
Chrome: 61.0.3163.100
Node.js: 8.9.3
V8: 6.1.534.41
Architecture: arm

C# Extension version:
1.17.1

Steps to reproduce

Hit F5 from a C# console application.

Expected behavior

Program builds and runs, and stops at breakpoints.

Actual behavior

[WARNING]: Processor architecture 'armv7l' is not currently supported by the .NET Core debugger. Debugging will not be available.

[gregg-miskelly]

@m-brooks my understanding is that VS Code doesn't have an official version for Linux ARM. Is that correct?

[m-brooks]

Hi Gregg. I believe so, although it also appears that Microsoft have provided an ARM flavour of the C# extension for VS Code, because I installed the MS C# extension and it's working. This does therefore leave some question over their intended direction, which I suppose is the hidden question inferred by my issue above. Having gone through all the hoops that I needed to in order to get VS Code running on a Raspberry Pi I was genuinely surprised when I hit F5 and got the above message. It would be so cool if someone in Microsoft were to port the debugger to ARM as that would complete the jigsaw and we would have the ideal low cost teaching platform. Without a working debugger it's fairly useless - a case of so near but yet so far.

Regards,
Michael

[gregg-miskelly]

Short answer: This isn't something we can currently help with. The debugger is only licensed to run in official version of VS Code. So even if you had a version for ARM, it still wouldn't run because the license checks would fail. So microsoft/vscode#6442 needs to be addressed before this can be implemented.

I will leave this open in case the VS Code team decides to more officially support Linux ARM.

More details in case you are curious: The C# extension has 4 parts to it --

• The 'entry point' is a bit of JavaScript that interacts with the VS Code UI and glues everything together. VS Code itself provides the version of node that this runs on, so as long as VS Code works, this will work.
• The language service is implemented in C# and runs on mono. It doesn't fully support ARM in the sense that it doesn't ship with an ARM version of mono. But from your description, it sounds like everything is fine as long as your box has a new enough ARM mono version installed.
• The debugger is implemented in a mixture of C# and C++. Most of this is available for Linux ARM because we support Linux ARM as a remote debugging target. But currently we don't package it together for VS Code since there isn't an ARM version of VS Code to support.
• The Razor language service is implemented in C#. There would need to be additional packaging work to support Linux ARM, but otherwise I believe things should just work.

[m-brooks]

Gregg, many thanks for the response and the details re the extension. In case it's of interest, rather than installing Mono I installed the official Microsoft ARM build of .Net Core 2.2 (my understanding is that this is a completely separate code stream from Mono, but I realise I could have picked this up wrongly). My VS Code is Jay Rodgers's build (headmelted.com).

Fingers crossed that the VS Code team have both the desire and bandwidth to tackle a Linux ARM version - to my mind it's just the perfect complement to the Raspberry Pi.

Best regards,
Michael

[joaomoreno]

@gregg-miskelly Great news, the first bullet point has been addressed, since the latest Insiders already supports ARM as a remote SSH target: https://twitter.com/joaomoreno/status/1138379435839754240

Now all we need are the following 3 bullet points... 💪

[gregg-miskelly]

@joaomoreno very cool! But to be clear, I am not sure this changes things too much --

• If you want this because you just want to debug on a Raspberry Pi, but you will run VS Code on an x64 PC - that was actually something that the C# extension has supported for a long time via remote debugging. Some folks might find VS Code remote an interesting option as an alternative, but there are some downsides of that way too since you are running Omnisharp, which is pretty demanding, on ARM.
• If you want this because you have a very inexpensive ARM-based computer that you would like to use as your PC, then you probably need full VS Code support (and probably a .NET SDK)

[thesamesam]

@gregg-miskelly My use case is using a Pi as a base to connect to from other devices through the Remote feature, but even though vsdbg runs on the Pi, the extension doesn't seem to work (complains about architecture).

I was able to get Omnisharp running without too much trouble. Did not try Razor as I was trying to run a console app.

Given that a remote instance of Visual Studio Code would end up running the debugger, it would now be permitted under the license?

[gregg-miskelly]

@thesamesam there is no licensing reason why that scenario can't work, but I think you would be better off using remote debugging instead. Firstly, because it works today, so right now, it is the only option. But also because, at least if you have a reasonably sized project, the language service (Omnisharp) can be compute-hungry. So you probably would rather use your local processor, than run it on the comparatively under-powered CPU on the Pi.

[thesamesam]

@gregg-miskelly Oh, I misunderstood then. I can see why the processor might be a problem. The main reason I'm keen on it is having the filesystem constant when I'm changing machines.

At the moment, when I tried Remote (Insiders; Nightly SSH) + Pi + C# extension, I had the armv7 error for debugging and it didn't seem to download or fire up OmniSharp either (so nothing happened, bar the error). I'm not sure if I need to report this somewhere else though?

[gregg-miskelly]

If we fixed this issue, the remote scenario would also be addressed, so no need to open a separate issue.