Description
The emake client failed to create an operations file in the object cache. The cache was not updated, and temporary data may have been left behind.
The final portion of the error message is provided by the operating system, and indicates what exactly went wrong.
Reasons
The emake client maintains an "asset directory", which provides a memory of past builds to help future builds. Certain subdirectories of the asset directory correspond to cache "slots" used by Parse Avoidance and JobCache.
Emake wanted to update a cache slot, and created a temporary directory to accumulate the new state of that slot. But when it tried to create the operations file in that slot, it failed to do so for some reason.
See the trailing portion of the error message for the specific error reported by the operating system.