Hi BonnieCase, I did this on a 4gb rpi4, so memory was not an issue even with the -j4 tag. I did use a second terminal with htop to check how it is doing from time to time and 512mb is definitely not enough as compiling cmake spiked the ram usage to a little over 1gb. Are you trying to build it on a rpi2/3? If you don't care about building the image yourself, you can always use the prebuild docker image. If you do want to compile it yourself, I suggest to add at least 1gb of swap memory and remove the -j4 tag from the dockerfile to force it to build it on one core, hence use less memory.