This question already has an answer here:
I tried updating to Catalina, but it got stuck on not having enough disk space. It says I have to quit the installer, select a start disk and boot from that, but my system's drive is not in the list of drives that I can select...
So, instead, I started the Terminal, went to the drive through that and I started deleting things. But every time I run
df I don't see a change in the amount of disk space. Between reboot changes are persisted though, even creation of new files.
I then installed Mojave on an external drive and mounted the internal drive, it shows up as 52GB free (vs 12GB from
df). But when I run
df I still see only 12GB free.
I figure there is some sort of place where deleted files are getting moved to in order to provide me with some fancy restore magic for when the installation is done. Where is this magical place and how do I delete files from there so that I can continue the installation?
The answers here don't address my issue because I already know what was eating my disk space.