Bug Build time taking almost a day - URP

Hi, I am experiencing some weird, extreme long, build time since I got the latest Unity 2021.2.0b1

On the 2021.2.19a I was able to build it in around 10 seconds, and first builds around 3 - 5 minutes.

Since I got the latest, it has been around 15 hours and it is still going.

It seems to be stuck in Compiling Shaders Variants (which, for whatever reason, also compiles the Deferred even though I am just using Forward)

I am making a build for Windows. I am working with Multiplayer, I just wanted to do a fast test on the progress I've done.

I've worked on massive projects before, thousands of shaders, and the build was around 1 - 3 hours. (There were some PCs that was able to build that in 8 minutes, for unknowing reasons.)

My current project is still in early stages, very small, I am working alone and I deleted almost all shaders in the project.

Not sure if it is a bug or not, but it started at the exact time I updated to the latest version.

Thank you.

 

If you still have it, editor logs of the build process would be helpful

 

Hi, any advance in this topic? I have a similar problem in Unity 2021.2.0b13:
The "Compiling shaders" phase is taking a very long time in build, i think it should be a bug because it tries to compile high number of variants as seen in the next image:



This is not the first try on making a build, but every time I tried in "mono" ended with an "OutOfMemory" error after several hours stuck in "Compiling shaders".

This last build i'm making now is made in IL2CPP, but the only thing i see is that the build is a bit faster, but still slow for a non massive project, asset folder is only 5.9Gb and there are less than 10 custom shaderGraph-made shaders. Is this any known issue solved in a next patch? Or is it an isolated case, if i need to provide info please tell me what do you need.

Project is now in Unity 2021.2.0b13 using the Universal Render Pipeline.

Thanks in advance

 

Hi @LeonhardP , thanks for the advice, but the build is still taking too long so far;



I let the computer on while it was away, but i don't know if the hdd tuned off, so i will wait a bit longer to see if it can complete it or if it crashes, if you have any ideas on what can be causing this long times, i will be glad to hear and try any solution

 

Check your task manager - is Windows Defender running? You might try to add Unity install directory and the project directory from Defender's ignored directories, as it might be continually scanning all the temp files created by the shader compiler.

 

Hi @Baste , Windows defender is not running, but i have another antivirus, i don't know if it is the problem as in task manager all the CPU usage was used by "unity shader compiler". Anyway, it has ended shading compiling right now, so i will try another build after the build had finished without the antivirus to see if anything changes.

 

@jaguero Do you have URP asset assigned to your main graphics RP asset? If not, I think the shader preprocessor takes early out and doesn't strip ANY of your URP shaders (means it will take forever to get them compiled then).

 

Hi @rz_0lento . Yes, i do have it


I tried "strip unused" and "strip all" and i didn't notice changes in time.

Actually I'm trying to change the project to an SSD to see if the problem is the HDD.

 

Well, it crashed again, dont know if having a very small SSD could be the problem

 

Well, apparently changing to the SSD solved the problem, time now went from 19 hours to less than 30 minutes, don't know if it could be better, but at least is a reasonable time, besides not having the problem in previous versions, maybe the antivirus overcharged the HDD as @Baste suggested.

Thank you all for the help!

 

Builds are thousands of tiny files so seek time on a traditional hard drive is the bottleneck rather than data itself. SSDs are good at this. But 30 mins for a build is too much even for a final game. In these scenarios one is best off separating assets that won't change into asset bundles and then just compiling code becomes the main thing for each build you do - and should take a few minutes at most.

The exception being shaders - these can be a hot mess for compile times but can also be cached if I'm not mistaken, between builds.

 

Can attest to the last point. On my project the first build after a reimport for Android/iOS takes about an hour (all about those shaders), all subsequent ones are within 5-10 minutes.

 

This is also happening to me.

My project now takes 2 hour + to build if the shader is changed. Previously this takes around 30 minutes tops.
And every time I switch build target, it's like all the build cache is cleared that every variant needs to be re-compiled again. HDRP seems normal, only URP is experiencing this issue.

 

Happening to me too. I have tried all the above fixes. Just building the simple construction sample scene takes hours. You guys added A LOT of variant keywords.

 

Hey,

This is reproducible for us as well. Incremental game build went up from a few minutes to closer to 1 hour.
Empty URP example project incremental build: 40 -> 102 seconds

Bug report 1383867

 

Been testing since 2021.2, and all the way up to 2021.2.6f1, super long build times, mostly due to shader stripping I believe. In 2021.2.6f1 particularly, unverified but it seems to have made the build size larger as well.

 

Since upgrading to 2021.2.8 my builds take 2-3 hours instead of 10 minutes. 95% of the time is spent on our shaders. Shouldn’t these be cached?

Never had these issue before upgrading.

Each shader does:







then again:


Om on an SSD.

 

I am already stripping everything:



Builds still take around 3 hours.

 

Have tried all the various shader stripping toggles, still takes a very very long time for each Windows build compared to Unity 2020.3

 

The problem reproduces in the URP Template project and that's what has been reported and confirmed by QA.

 

Same issue. This is beyond annoying. Waited around 30 minutes before quitting the build. There's hardly anything in my scene. It seems to have triggered it by regenerating lightmaps.

In 2021.2.10f1

 

Same. Build was taking up to 45mins so I just cancelled it. Cmon URP..

 

2021.2.14f1 contains a fix which reduces the magnitude of the problem.

Now our main project builds only 4x slower than on 2021.1, versus 10-12x slower.

 

I dont dare upgrade any more until the LTS version comes out. But thats something at least

 

Hi @LeonhardP

i have same issue in Unity 2021.2.8 to 2021.2.15









I asked the publisher from BetterLit and he gave me the hint that the shader compiler is currently broken in 2021.2.x.

Build time from build Adressables and build goes up to 5+ hours.
The PC becomes close to unusable in this time because of 50% to 90% CPU is used.

https://forum.unity.com/threads/the...urp-hdrp-standard.1088851/page-5#post-7926304


Could you give us some clarity about this?

 

I work on this project since 3+ years.
It takes 5 to 8 hours on 90% CPU.
All other Unity versions before 2021.2.x did not have the problem and did the build in max 30min even after reimport.
This problem also happens on HighestEnd workstations.
Intel(R) Core(TM) i9-9940X CPU @ 3.30GHz 3.31 GHz

Total Cores 14
Total Threads 28
Max Turbo Frequency 4.40 GHz
Intel® Turbo Boost Max Technology 3.0 Frequency ‡ 4.50 GHz
Processor Base Frequency 3.30 GHz


I often saw this BetterLit Forward 0 to 10368 progress bar.
It took some/one minutes to finalize. Not 3h+

e.g. The progress on the screenhsot on 2497 of 10368 stands there for 10to 15min before it iterates to ~2550.of 10368.

Did the Shader complexity of the BetterLit forward changes as much in last HDRP releases?

 

The fact still remains that all of us here had "normal" build times of 10-20 minutes before upgrading Unity to 2021.2.x, and now it takes us several hours. If you actually read through the thread youd see that all of us has tried all possible settings youve suggested and nothing helps.If it was because it "used the cache before", then why doesnt it anymore?

I really hope you guys don't close your eyes to this problem going forward because right now it's just not good enough.

 

I guess we'll have to suffer though our 20 hour build times until it's addressed.

 

Nice to hear that it is being adressed at least!

 

Is there a workaround we could do in the mean time?

 

In HDRP it started with 2021.2.15+.
TransparentBackface and HDRP Lit also takes hours to build.

 

Could you give more details on what regressions are being fixed and how? One of our production titles on Unity 2020 (BRP) with hundreds of shaders compiles in less than 10 minutes. A newer project on 2021.2 (URP) with barely 10 shaders takes hours...

 

Hi,

We're also facing some issues in shader compilation times with URP (with no Shader Graph use):

Same project in 2020.3.30 loads in Editor in a few seconds, builds in less than 1 minute.

In 2021.2.17 however, the same scene takes 10 minutes to load in Editor and build takes like hours? (all due to shader variant compilation).

It's same project so I tag this as a perf regression. Cases #1416284 & #1416268.

 

Some info on the bug report:

It turns out the shader is forced to be unrolled in 2021.2.17 (due to a texture sampling macro that's resolved to a sampling with no explicit LOD in a loop). The URP base code in 2021.2.17 could be more extensive so that could be causing too many instructions in the resulting shader. We're seeing this error "shader can't be unrolled..." in some machines that could be related. We fixed that on our side by forcing LOD sampling, so it's ok now.

Since the same shader compiled fine in 2020.3 LTS, I guess some change along the chain of the sampling macro or URP increased base code caused the instructions overflow, so the bug repro can still be useful to investigate potential optimizations during the shader compilation.

Cheers

 

Just made my first build with 2021 LTS, this is still an issue. Its a bit silly you call it a "production ready environment" with this issue still not fixed. Are we just gonn have to deal with 5-hour builds from now on if we want to use Unity? If thats the case I def wont use the engine for any future games.

 

Hi,

Is this applicable to URP as well?