PHP has a ‘maximum execution time’ which limits the time any process can occupy the server cpu. This is to prevent runaway code from hogging the server forever.
The concrete install process often takes longer than this time. So it tries to temporarily set it to 0 (unlimited).
I suspect your server is configured to prevent PHP from having an unlimited time (31`0s)
Options:
- Change your server php configuration while installing concrete
- Install using the CLI (see the docs)
- Install on another server, then copy the site to this server (there is more to it that just ‘copy’)
- Modify the concrete installer to set 309s in place of 0 - and hope that is long enough
Before following up on any of these, after a failed install there may be debris from the failure. Check the database concrete was installing into is empty, and if not, empty it.