VPS with 1 core and 512 MB RAM. I just checked, not really a hour, it spent 25 minutes and then failed with "no space left on device". Right now there's 4.9GB free, so it takes at least around 5 GB disk space which is an issue as well.
Building on separate computer will work, of course, but it makes everything more complex.
Building on separate computer will work, of course, but it makes everything more complex.