How do you purge purgeable space on an SDD mac?
I have a 13" MacBook Air with 250GB SDD drive. My disk started nearing capacity lately so I decided to try the new feature of moving Documents and Desktop files to iCloud. That seemed to work as all files are now in iCloud. At that point I decided to import photos into Photos, also taking advantage of its ability to store files in iCloud and automatically manage memory usage on the SDD. After doing some imports in Photos it alerted me that my disk is almost full. When looking at Storage, it appears that 100GB of space is 'Purgeable' and that I have nearly no 'free' space remaining. The documentation makes it sound like this is exactly what iCloud storage is for - to move rarely used files off of local storage to make room for new files. Unfortunately I am not able to purge this purgeable space and the OS seems to not make use of it for new files either, so it amounts to dead space. I'm not able to import new photos, or even create new files due to lack of available disk space.
I am not running time machine, and I already manually purged all files that were still in Downloads. There are no other files to purge as they are already in iCloud. Any suggestions for how I can make this work without bringing all my files back from iCloud and manually purging more of them?
MacBook Air, macOS Sierra (10.12.2)