When building a fairly new project in UE5 (handful of C++ files) it often hangs on this for 10-15 minutes, with nearly 0 CPU use by Visual Studio.
1>Determining max actions to execute in parallel (6 physical cores, 12 logical cores)
1> Executing up to 6 processes, one per physical core
1>Building 24 actions with 6 processes…
yep. sometimes it do that.
I was having issues with that a few days ago, and I popped open task manager, and noticed that i had 16 cl.exe processes running but they were all almost 0 cpu usage. I pulled out another utility I use called Process Lasso, and it told me that all 16 of the cl.exe processes were for some reason running on a single core at Below Normal priority.
I used that app to set them to run on all 16 cores at normal priority , and it stopped doing that delay thing.
Thanks for the reply. I’ll see if something similar fixes my issue.
I’m still getting this issue. I haven’t been able to find a solution. I tried updating my Visual Studio, even updated Visual Studio to 2022 (was using 2019) and I still get issues with it hanging on building.
No CPU use at all after hitting build. On a brand new project with default code from template, I get
1>Building 4 actions with 4 processes…
It sits on this for 10-15 minutes at minimum. No CPU use. CL.exe isn’t running.
When it finally does something, it builds in about 5 seconds.
Changing a single line in a C++ file means 20 mins to restart editor.
what build configuration are you using? I just discovered today that test builds spend about 30 minutes in the linking process 
If you don’t have SSD it can really slow things down, VS likes to cap out disk usage
Building Development Editor. The hang I’m getting is long before it even tries to do linking. Last night it hung on this for 35 minutes. Then when it started actually doing something, it took 44 seconds to compile, link and start running.
I don’t have enough SSD space for projects, though I guess I could try moving it to one and see if that makes a difference.
FYI, My current project only had 4 cpp and 4 h files in it. Its essentially still the template top down C++ project.
I have had it do weird things before. I use a program called Process Lasso to force some processes to maintain running at Normal priority and full CPU affinity sometimes (i also use it to force them to run at Below Normal or adjust cpu affinity when I need to use the computer more than I need the builder to complete fast), which can sometimes make huge differences. I’ve often caught windows or some other actor forcing processes to only run on 1 core, which is weird and slows things down a lot.
Even if you don’t use it like that, Process Lasso can give you a really good overview of what is happening.
try to change the BuildConfiguration.xml, it works for me.
<?xml version="1.0" encoding="utf-8" ?>
<Configuration xmlns="https://www.unrealengine.com/BuildConfiguration">
<WindowsPlatform>
<PCHMemoryAllocationFactor>100</PCHMemoryAllocationFactor>
</WindowsPlatform>
<LocalExecutor>
<ProcessorCountMultiplier>1</ProcessorCountMultiplier>
<MaxProcessorCount>8</MaxProcessorCount>
</LocalExecutor>
<ParallelExecutor>
<ProcessorCountMultiplier>1</ProcessorCountMultiplier>
<MaxProcessorCount>8</MaxProcessorCount>
</ParallelExecutor>
<BuildConfiguration>
<bAllowXGE>false</bAllowXGE>
</BuildConfiguration>
</Configuration>
This! It allowed me to take advantage of all CPU cores. I managed to reduce the compile time from ~600 seconds (10 mins!) to ~100 seconds (1.6 mins), since my CPU has 6 cores.