I can confirm "No memory left" problem. My system is 32-bit Laz 1.8.3 + FPC 3.0.5 on Win10x64. I didn't have that problem with previous 1.8.1+3.0.5. I have Intel 4670 with 16GB. It happens when you install looots of packages with or without OPM. When it happens you have to uninstall at least 10-12 existing packages and it then allows you to install the package you thought was problematic. Unfortunately every "problematic" package passes after this big package uninstall happens first.
I would not know normally, but I am testing ct4laz repo and it needs lots of OPM packages and also many ct4laz packages. So I can reproduce described behavior. You install packages normally, and after a while when it shows, packages can only be compiled but not installed. Only some very small package can install then. After that not even small. I have the same problem with optimized and normal IDE buildings. Clean build does not help. Since this was a fpcupdeluxe installation, I have a clean install that I zipped. I can reproduce the problem when starting from that clean zip archive.
We both have Win10 in common.
I will test if old 1.8.1+3.0.5 now has this problem, too.
In my first iteration of tests I had only 32-bit Vivaldi browser running. In my second iteration I had only Total Commander running. Therefore I do not think I was out of resources (although I didn't check at the time).