Random Missing Assembly errors when building in batchmode

We're getting random missing assembly reference errors on our build machines with Unity 2018.2.11f1. I'm not sure I have solid repro steps unfortunately as it seems to happen kind of randomly with different files in multiple projects.

Our setup:

• Code is split up a fair amount using Asmdefs
• Using Teamcity and running unity builds via a python script (batchmode, obviously)
• Scripts are run on dedicated build machines using Local Cache Server
• SVN revert and cleanup are called between each run

Errors look like:

Assets/Scripts/Audio/AmbiencePlayer.cs(11,14): error CS0246: The type or namespace name 'RandomAudioEmitter' could not be found. Are you missing an assembly reference?

where AmbiencePlayer and RandomAudioEmitter are files in the same assembly, but both rely on stuff from other assemblies. At the moment is always these files that throw errors. Running the build script again does not produce the error, even though nothing has changed.