Why does UE5 compile every module every time?

After upgrading my 4.27.2 project to 5.0, every time I make even a tiny change in one of my game’s source files the build tool seems to recompile a whole bunch of modules (seems to be all my plugins), so my build times went from < 10s to over a minute. The link steps take the longest. I’m not building the engine from source BTW. I looked through the migration guide and couldn’t find any obvious reason it would be doing this. Can anyone help me please?

I’ve attached my build log.
ue5_build_log.txt (15.2 KB)

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I’m noticing this as well in the binary dist of UE5 from the Launcher. What’s odd is that (for me at least) the plugins that are being recompiled are plugins that come from the marketplace. These, of all things, shouldn’t need to be recompiled.

I’m also using the launcher version, and all the plugins I’m using at the moment are also from the Marketplace. Glad to hear it’s not just me, hopefully someone has an answer for us!

I’m just guessing but it might the bUseUnityBuild setting you could add to your target.

I’m just guessing but it might the bUseUnityBuild setting you could add to your target.

That reduces the number of files to compile from 55 to 44 but otherwise not much changed unfortunately.

How to prevent plugin recompilation - Pipeline & Plugins / Plugins - Unreal Engine Forums

The solution (add bUsePrecompiled = true to plugin build.cs files) seems to have worked for me. I still feel that something is off as this shouldn’t be necessary with Marketplace installs.

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The solution (add bUsePrecompiled = true to plugin build.cs files) seems to have worked for me. I still feel that something is off as this shouldn’t be necessary with Marketplace installs.

Thank you! At least we have a workaround now; works for me too. I won’t mark this as the solution yet as there’s clearly something wrong somewhere. I’m not sure how one could get Epic’s attention, hopefully they have staff on the forums.

I submitted a bug report to Epic on this issue.

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I’m getting this issue on a lot if not all installed marketplace plugins right now. Build times have gone from 5 seconds to upwards 50s. Adding bUsePrecompiled = true in the build.cs doesn’t work for some plugins, such as Multi Object Renaming Tool (MORT). It will cause the editor to throw an error upon launch.

@Acriax Sorry to hear that bUsePrecompiled doesn’t work for all the plugins. It’s a less than ideal workaround for sure. I’m really hoping that the bug report submitted by Recursoft gets some love; I can’t imagine this is only limited to a handful of people. Having said that, Epic is no doubt swamped since the release.

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Just wanted to add a few keywords because I didn’t find this issue and was stuck a couple of hours reverse engineering the live coding feature since I was reported this problem:

(The missing keyword were: Live Coding plugin recompilation every time it is triggered)

Also, I wanted to bump the topic because the amount of people it may concern is veeeery high.

Another workaround I found is to move the plugin’s project folder from the engine folder into your project/Plugins folder so that it builds alongside your project.

This makes your project more portable too, so I think I’m actually going to be doing this regardless for any plugins I acquire from now on.

I think 5.0.1 which was released today may have fixed this.

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I think 5.0.1 which was released today may have fixed this.

@Recursoft Yep you’re right, looks good now! I’ve removed the bUsePrecompiled flag from all my Marketplace plugins and they are no longer included in every build. Thanks for logging the bug for us!

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