got the same message installing 19.04 on a macbook box with 2GB RAM
I looked in /var/log/syslog file (as the error message suggested) and saw this up a ways:
I/O Error ubiquity OSError: Errno 28 No space left on device
using the "continue anyway" button it then results in "the installer encountered an unrecoverable error. A desktop session will now be run so that you may investigate the problem or try installing again"
After running the install from a "live cd" so I could monitor the output of "df -h ." while it was installing, sure enough it runs out of disk space.
work around: uncheck "install third-party software for graphics and wifi"
or don't connect to a wi-fi (or wired) network. Uncheck either one and it works. Turns out in this case it is downloading and installing the third party nvidia driver and it "exhausts" the RAM disk drive.
It seems that it installs these new third party packages (nvidia-340, bcmwl-kernel-source) before doing the setting up/mounting of the install disk (which would include some additional swap space on that disk) so it blows up.
It would appear that checking the "download updates" doesn't suffer from the same problem.
sometimes it says "ubi-partman failed with exit code 10" gdisk partman
workaround: install without 3rd party (or without wifi) and then install the 3rd party from the "software updates -> additional drivers" pane after install.
You may want to still install with wifi since you get some "security updates" if you do, from the get go.