As part of trying to add RISC-V support, I ran out of space on the server. It looks like it only has about 1Gb left, which wasn't enough for me to create a docker image, let alone build anything on it. Space use is as follows - the machine only has a 100GB disk attached:

• 51Gb in the download directory
• 7.7Gb in use by Docker
• 8Gb in use by staging
• 26Gb in use by ccache (Roughly 4½Gb per platform)

SO we're at the limit of what we can have on this machine - it just so happens that trying to add riscv64 has sent it over the edge. I've removed my attempt at a docker image to put it back ot where it was before, but we'll need to do something with this but we were probably going to hit this pretty soon regardless. Options?

1. Get more space on the server, or provision another one with more space
2. Don't keep so much in the download directory (prune more of the older releases?)
3. Stop using ccache (perhaps a temporary measure) or reduce the size of it for each container
4. Something else?