Operating system: Windows-7-6.1.7601-SP1 64 Bits
Graphics card: GeForce GTX 560 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 388.59
Blender Version Broken: version: 2.81 sub 2 , branch: master, commit date: 2019-08-16 18:51, hash: rBe8ffe25eb111
Short description of error
Lookdev never unloads the HDRIs given to it. This results in runaway memory usage, and eventually an OOM crash.
Exact steps for others to reproduce the error
Install a large number of lookdev HDRIs. (50 or more)
Observe memory usage. Several gigabytes will be taken up.
Observe memory usage. Blender will use a minimal amount of memory at this point, as expected.
Open the lookdev pop-up, and try to change the HDRI. (Alternatively, open the HDRI manager.)
Observe memory usage as Blender loads in the "thumbnails".
Pick a HDRI and close the pop-up. Memory will still be taken up by all the other ones, no matter how long we work on the scene.
A user's HDRI collection can be potentially large, and the current import and load behavior is very inefficient. Copying the images to the settings folder can have additional bad consequences. (small partition, backup software trying to pick up the HDRIs, waste of disk space when several programs are using the same collection)
Consider importing the images as path+thumbnail only.