Bug Unity Collections: 1.0.0-pre.3

Hello, this is my first post to any Unity forum, so apologies in advanced if this isnt the proper place.

I saw there was an update package for the Collections (com.unity.collections) package. Since updating, the console outputs this compiler error on a script I cannot attempt to fix, since its in the unity Jobs package.

Library\PackageCache\com.unity.jobs@0.8.0-preview.23\Unity.Jobs\IJobParallelForDefer.cs(77,85): error CS8377: The type 'U' must be a non-nullable value type, along with all fields at any level of nesting, in order to use it as parameter 'T' in the generic type or method 'NativeList<T>'
​

I tried to rollback to the previous collections version, and that didn't work, although that could be because I didn't have the exact version number. There was also no update to the jobs collection that I saw. I cant proceed with my project at the moment, unless I decided to re-import everything in a new project and reinstall all the packages. My game also makes heavy use of the jobs system because I honestly enjoy fiddling with it and seeing how insane I can make a scene while still getting 300+ frames.

If anyone has an update, quick fix, or tip for this that would be awesome! Should anyone need to see my code I am more than willing to put it somewhere to share as well, but it didn't receive compiler errors BEFORE I updated the collections, and again, on double clicking the error it only brings me to a package script I cannot edit.

Its also worth noting this is the only thing I can find that pertains to this issue:

https://issuetracker.unity3d.com/is...nmanaged-structs-as-containing-nullabe-fields

 

Are you using jobs and this stuff? If not, remove it. Unity tends to barf lots of unneeded crap into projects and cause issues with new developers.

I've scribbled about it before and how to edit the manifest.json to prune unneeded junk packages out:

https://forum.unity.com/threads/temp-unityengine-testrunner-dll-error.1133938/#post-7287748

 

Yes I am using Unity's job system package. I do remove unnecessary packages all the time but not this time. I cant remove the job system without crippling my code.

 

Well the fastest solution I can see is to revert the update to those collections... this is why it is a great idea to use source control, which would give you a history of changes to your Packages/manifest.json file and let you instantly revert to a known version.

I tried just now to track down how to even get the jobs preview package into my project and it's vanished behind yet another insanely horrible UI that (according to googling) means I need to find a git repo of the jobs package to even get the jobs package into my project. What a colossal mess!

Maybe there's someone who can help you over on the Jobs forum on this board? Or go back to an older version of Unity, make fresh project, add the jobs, take that manifest.json and jam it into this project. Yuck.

Good luck. What a mess!!!

 

Update: checked around some old projects and found one from 2019 using Jerbs.

The relevant package entries are:

    "com.unity.burst": "1.0.4",

    "com.unity.collections": "0.0.9-preview.19",

    "com.unity.entities": "0.0.12-preview.32",

    "com.unity.jobs": "0.0.7-preview.12",

    "com.unity.mathematics": "1.0.1",

 

Thank you for providing me with some packages! Usually I use source control, but 1, I'm rather bad at it, and 2, I dont have a good excuse really, I'm just bad at understanding it. Thankfully Unity provides all the relevant packages here:

https://docs.unity3d.com/Packages/com.unity.entities@0.17/manual/install_setup.html

I understand why they did it, and its to keep people from being mad about things like this because its easily available in the package manager. Using the wrong packages(see above), can and will break projects especially since Unity is seen as the 'entry' into game development and would leave a lot of new game-devs discouraged from trying new packages.

With that said, I did post this to the Jobs board that I just found. I linked this post, so I hopefully can hear a reply soon. Thanks again for your help Also i have to say, the beta package Unity UI looks really nice and isnt 'artifacting' like my previous install.

 

I just updated and I'm getting the same error.

 

I also need Jobs. This was fixed by reverting Collections 1.0.0-pre.3 back 0.17.0-preview.18 for me. I had to edit this in the manifest.json file because it was not available in the package manager. I just made sure the line with com.unity.collections had " "com.unity.collections": "0.17.0-preview.18" Be sure to backup your project and json file before doing this just to be safe. As a further note I need Jobs (0.8.0-preview.23) for Vegetation Studio Pro along with Burst (1.5.4), Mathematics (1.2.1) and Collections(0.17.0-preview.18). These seem to all work well together and are the most stable combination in my situation. Best of luck to all you Unity game devs out there!

 

Is this going to be fixed by unity presumably in the next Jobs update?

 

Same issue. Still waiting for a fix.

 

Same issue

 

Remove Collections. It Is built into one of the other packages now.

 

Thank you!! That was it.

 

Thankyou Mr Internet Person! Solves me troubles too...

 

Thanks, darkwingfart !!! No it's working! You saved many of my time! The shortest and best solution... THANK YOU!!!

 

Can't remove collections because Jobs and mathematics depends on it. Any other working solution without removing anything?

 

Mathematics is also included in entities now. You should probably remove all the ECS packages, install entities, and see if you still have dependency issues. I doubt you will, and I'm assuming you're not on the latest packages.

 

Bumping this again; I'm basically stuck on collections 0.15 or something because I use unity physics (0.6.0-preview.3, which hasn't been updated since January). This is some serious DLL hell that doesn't need to be like this.

 

Library/PackageCache/com.unity.jobs@0.5.0-preview.14/Unity.Jobs/IJobParallelForDefer.cs(77,85): error CS8377: The type 'U' must be a non-nullable value type, along with all fields at any level of nesting, in order to use it as parameter 'T' in the generic type or method 'NativeList<T>'

Just got this message.. again.. after reverting to an old version of collections and then updating a package it's now dependent on the latest collections pre-release:

Collections 1.0.0-pre.5
For me it's always the IJobParallelForDefer that throws the error because some package has a managed type for U.

 

Remove Collections and install com.unity.entities

 

Hi i have a similar problem. I'm using Unity Version 2020.3.18f1 Personal on a Mac and a get this error.

Library/PackageCache/com.unity.entities@0.17.0-preview.42/Unity.Entities/Serialization/BinarySerialization.cs(47,81): error CS8377: The type 'T' must be a non-nullable value type, along with all fields at any level of nesting, in order to use it as parameter 'T' in the generic type or method 'NativeList<T>'

The other problem I'm having is that I can't downgrade or remove any package.

 

Have the same problem:
Library\PackageCache\com.unity.entities@0.17.0-preview.42\Unity.Entities\Serialization\BinarySerialization.cs(47,81): error CS8377: The type 'T' must be a non-nullable value type, along with all fields at any level of nesting, in order to use it as parameter 'T' in the generic type or method 'NativeList<T>'
And cannot delete Collections, there is the screen of installed packages and their versions.

 

It helped to solve my issue thank you.

 

I was getting the same errors, and installing com.unity.rendering.hybrid didn’t work at first. My problem was that I had installed Animation Rigging before trying to install this or the entities package directly, and animation rigging was using a different version of jobs (and burst I think) than entities required. I just uninstalled everything but animation rigging, the math package, and the burst package and installed the hybrid renderer. I got a warning burst needed to be a different version, but it changed that by itself successfully. Then everything was working fine. So, if you’re having problems, and don’t want to mess with the manifest file, try uninstalling everything related to ECS first, then installing the hybrid renderer. Hopefully Unity gets all these dependency chains/conflicts worked out soon.

 

We are in the same boat, we are using the Netcode for GameObjects, which requires Collections 1.0.0-preview.5, our project is using Entities, which we unfortunately had to temporary remove, because of the conflicts that has broken our project, hoping Unity fixes these issues soon, otherwise might have to remove Entities permanently and rewrite code

 

could we get a fix for this? I am running in to this issue as well. I don't know of a workaround and doesn't seem like there is any compatibility for netcode for gameobjects and hybrid renderer 2

 

Use mirror.

 

Seems like this is still an issue. This answer also worked for me

 

How to uninstall collections?

 

How to remove collections? I can't from package manager

 

Packages/mainfest.json is the proper place to add/remove packages in the project (check packages-lock.json file for automatically added dependencies as well.)

 

Same Problem here after downloaded Megafiers 2 to Rival tutorial sample project:

Library/PackageCache/com.unity.jobs@0.2.10-preview.13/Unity.Jobs/IJobParallelForDefer.cs(73,85): error CS8377: The type 'U' must be a non-nullable value type, along with all fields at any level of nesting, in order to use it as parameter 'T' in the generic type or method 'NativeList<T>'

Any idea how to solve it ?

 

update: Problem Solve...Update Jobs to 0.70.0-preview.7 and the error was gone...

 

I have a similar issue when trying to use 3 editors on a project with symlinked folders (the only sane technique we could think of to develop our multiplayer project).
We symlinked only `Assets` and `Packages` (the latter contains `manifest.json`).

The first instance works fine, the second instance works fine, but for whatever reason the third one keeps failing to compile:

Library\PackageCache\com.unity.jobs@0.8.0-preview.23\Unity.Jobs\IJobParallelForDefer.cs(77,85): error CS8377: The type 'U' must be a non-nullable value type, along with all fields at any level of nesting, in order to use it as parameter 'T' in the generic type or method 'NativeList<T>'​

I tried deleting the Library and restarting that third instance several times, making sure each instance is the same Unity version (2021.3.5f1), every time it fails compiling what it generates inside PackageCache. I even tried without even opening the other 2 working instances, had no luck. This particular project is broken despite being virtually a copy of the others.
This makes no sense to me because all 3 instances use the same symlinked `manifest.json`, and they have the same project settings...

Edit:
Turns out all 3 instances would no longer restart because at some point the Unity Editor modified `manifest.json` behind my back...

"com.unity.collections": "0.15.0-preview.21",​

Became

"com.unity.collections": "1.2.3",
​

I reverted back to `0.15.0-preview.21` and that error went away [for our project].

 

Just wanted to say you really saved my bacon here, was panicking as this error happened after installing Megafiers as well. Such a niche occurrence but you happened to post your thoughts here so I am really grateful. Thank you!