FileSystemWatcher not implemented on .NET 4.x with .NET Standard 2.0 only?

@strich @JoshPeterson

Case number: 1066732

WORKS!!

Version: 2018.2.1f1
Scripting Runtime Version: .NET 3.5 Equivalent
Scripting Backend: Mono or IL2CPP
Api Compatibility Level: .NET 4.x
Player: Windows

WORKS!!

Version: 2018.2.1f1
Scripting Runtime Version: .NET 4.x Equivalent
Scripting Backend: Mono or IL2CPP
Api Compatibility Level: .NET 4.x
Player: Windows

DOESN'T WORK!!

Version: 2018.2.1f1
Scripting Runtime Version: .NET 4.x Equivalent
Scripting Backend: Mono or IL2CPP
Api Compatibility Level: .NET Standard 2.0
Player: Windows



With .NET Standard 2.0 I get the following error:

According to this page "FileSystemWatcher" is part of .NET Standard 2.0:

https://apisof.net/catalog/System.IO.FileSystemWatcher

Inspecting Unity's fork of Mono I see this (fake) class:

https://github.com/Unity-Technologi.../System/System.IO/FileSystemWatcher_mobile.cs

In the original Mono repo there is no "FileSystemWatcher_mobile.cs" and it uses the same working implementation for all platforms:

https://github.com/mono/mono/tree/master/mcs/class/System/System.IO

I'm using a Microsoft open source library (.NET Standard 2.0) that has a dependency of another library that make use of this class and I can't use it...

https://github.com/aspnet/FileSystem

Specific usage of "FileSystemWatcher" class:

https://github.com/aspnet/FileSystem/blob/2.1.1/src/FS.Physical/PhysicalFileProvider.cs#L78

In the repro project I made it simpler and I only instantiate the "FileSystemWatcher" without any dependency and you can see that it throws that exception.

 

You already had it on the top of my post really big.

 

I am still getting this issue in 2018.3.0f2.

 

Hey, we've been getting this problem on .NET 4.x, for Android and iOS, both IL2CPP and on Unity 2019.2.9f1. We didn't have this problem previously on 2017.4.11f1 (we were using backend .NET 4.x already). We skipped Unity 2018.

I find it strange that neither this:
https://issuetracker.unity3d.com/is...on-net-4-dot-x-with-net-standard-2-dot-0-only
nor this:
https://issuetracker.unity3d.com/is...temwatcher-not-implemented-on-net-4-dot-x-api
are marked as regressions.

But I think we might have separate issues.

1. .NET Standard 2.0 doesn't have FileSystemWatcher implemented on Windows. I've never tested this. It is not our issue.
2. iOS and Android IL2CPP builds also don't have it implemented, even on .NET 4.x. This DIDN'T happen in 2017.4.11f1, at least on iOS (at that time we used Mono for Android).

Can you confirm if you know of this problem, @JoshPeterson? Will fixing 1. also fix 2.?

Unfortunately we didn't notice this problem on iOS and Android for a while, and have been developing on Unity 2019.2.9f1, so this regression is delaying our release because we need the FileSystemWatcher.

Will this fix exist in 2019.2.x? Upgrading to 2019.3 and risking breaking things is something to avoid for us right now.

Thanks!
Daniel

 

Thank you @JoshPeterson. If the team could back port it we'd really appreciate it.

But can you confirm that the fix for issue 1 and 2 is the same?

In the meantime I've confirmed that Mono Android builds don't have this problem. Only IL2CPP. I reported it as a bug, mentioning the other existing issues.

It seems that our issue is more similar to the second issue I linked (even though it's for Windows it's not about .NET 2.0 at all) but that one is marked as a duplicate of the first, and it doesn't look like it is a duplicate.

 

The release notes for 2019.2.10f1 also don't mention this in the known issues, which is a bit concerning considering the age of this bug. (I guess you can't possibly list ALL known issues, but this one break some builds silently, since the problem only happens at runtime).

 

@JoshPeterson OK, thank you for explaining. I noticed that my bug report actually didn't go through since the reporter is erroring when creating the archive, but in that case my report doesn't seem necessary anymore.

 

I would be grateful if you could update me later on the state of the back port for 2019.2. The final 2019.3 version is still a while away and even then updating may result in hidden problems in our project.

 

You mean 2019.2, right? If so that's really great for us.

 

Thanks a lot, we'll keep an eye on future release notes for 2019.2.

 

Finally they fixed it a year and a half later...

https://unity3d.com/es/unity/whats-new/2019.2.14

Scripting: Fixed an issue where FileSystemWatcher was not working on Windows when targeting .NET Standard 2.0 API Compatibility Level. (1066732, 1194583)

 

Still problem on 2018.4.15 Any fix for that?

 

SO what exactly We should do? I thought 2018.4 Is Long term Support version? but there wont be a fix? I dont understand

 

OK What we exactly see is :


I think thats not connected WIth net 4.x problem, Cause even after changing that the problem is still here, Even after removing all.dlls from projects and turning on new empty scene and click play, there is that error. IT is very simillar Maybe you already have experience with that?

 

This happend after upgrading from unity 2018.2. to Unit y2018.4 and the problem occurs every time I go to playmode, and cant build a game becasue of that (for playmode this is not to harmfull cause it happends only on start)

I read that it cant be traced cause could be from so .dlls, I removed all of it but it still here. Dont have idea how to fix that. Maybe it is because od some of Unity packages? that was automatically updated after umnity update? Cant see higher level error cause Console show nothing about it. If you have any ideas how to test it more, or isolate problem or files that could made that I will be grateful

 

Also we changed to NET 4.0 from 3.5 but cant remember if Bug was here right after upgrading unity to 2018.4 or after changing to NET 4.0

 

What about debugger, We tried it and nothing found. Will try again. But dont exactly know what we should track if we dont have certain script

 

What about debugger, We tried it and nothing found. Visual Studio debugger dont event show that error that is showed in unity console that screen I send above.

 

@JoshPeterson Its seems like we found it it is in "mscorlib.dll" in mono

file is in "Unity\Editor\Data\Mono\lib"

But dont exactly know how to fix now. Looks like unity bug?

We tested it also with visual to check is there any reference in any of our script project to that function. And nothing found. So it has to be a Unity Bug. Tried With NEt 4.0 api compability Standard 2.0 and Net 4.x no matter what we choose problem is always here.


EDIT:
We changed our project back to NET 3.5 and problem Dissapeard but The other problem is that we use Polybrush and Polybuilder package that work only on on NET 4.0 So that is unity bug and need to be fixed cause using NET framework 4.0 with unity 2018.4.15 will show that exception.

 

@JoshPeterson I reported That bug issue: 1214089 For now without fixing it we cant even build a game, or we have to resign from NET 4.0 and from polybrush that dont support net 3.5 and we already have prepared a lot of meshes with that so We cant resign from that. Let me know if you need any other info

 

using 2018.4.23f1 build and run il2cpp mode alway show:Unity: NotImplementedException: The method or operation is not implemented.[System.IO.FileSystemWatcher]

using net 4.0.Can't figure it out, a long term support version that doesn't fix the problem!

@Jakub_Machowski @JoshPeterson

 

Hi @JoshPeterson ,

I'm seeing this issue reappear in

2021.2.0a21

To reproduce it:

1. Download project files: https://github.com/andrew-raphael-l...tree/facb4abd713ef6a4b5654527a763539e7e0cf41d (

2021.2

branch, commit

facb4abd713ef6a4b5654527a763539e7e0cf41d

)
2. Open it with Unity

2021.2.0a21

3. Build it using Windows build config asset (ctrl+shift+b gave the same results)
4. Drag and drop

*.log

file over built executable and read it's player log (

C:\Users\USER_NAME\AppData\LocalLow\Andrew Raphael Lukasik\Unity Log File Reader\Player.log

)


EDIT: Case 1344045