Occasionally, the start time of the first process being built can take an extraordinary amount of time compared to the usual compile. Most times, this can last for a couple builds, but other times can get stuck.

This has been an issue that I’ve been running into when trying to build Dice and Sorcery with the Unreal Engine. And has definitely caused lots of lost time.

Background Details

Upon building the project, it will continue its usual motions, until it gets to Building X actions with Y processes..., where visually nothings seems to happen until 5-20 minutes later.

In the background, a process named cl.exe process will slowly climb from 5mb to roughly 600-700mb of RAM. While it climbs in RAM usage, the process is spending a lot of time reading from disc.

Once it reaches the 600-700mb, it immediately starts building as if nothing happened. As for why this only happens sometimes? I have no idea. It may have to do with caching or it could be Windows Defender getting in the way.

Fixes

Note that these fixes may or may not fix this issue permanently. These are mainly things I have tried personally and gotten some mileage out of.

1. Move The Project to an SSD

As it seems to be hitting the hard drive a lot, move the entire project to an SSD. This should make any repeat issues faster to resolve at the very least.

2. Delete Folders

Another possible fix is to delete the .vs and Intermediate folders. Then regenerate the visual studio project files.

This helps clear out older files, which may be getting in the way.