My environment is VMware, selected for other 2.6 kernel 32-bit and I am using the 2007.0 full LiveCD for x86. I don't know whether VMware is related to the cause. It just happens to be environment I'm in and it's hard to believe that if the installer was generally failing, it would not have been noticed by now. Anyway, I'm doing an advanced install where I created three partitions, /dev/sda1 ext3 for boot /dev/sda2 for swap and /dev/sda3 ext3 for root. I chose the CD for the stage and the installer copied the files to the root, which I could see in df filling up. But just after it is done, it reports installation failed. It claims there is supposed to an install log in /tmp, but there is not, not exactly, anyway. There is a compile_output.log.failed file, which seems to be saying Switching native-compiler to i686-pc-linux-gnu-4.1.1 .../bin/rm: cannot remove `//usr/bin/gcc': Read-only file system This is followed by many complaints of a read-only file system. It actually seems to be trying to act on the CD itself which doesn't make sense. It's as if it is not switching to /mnt/gentoo. I just also reported http://bugs.gentoo.org/show_bug.cgi?id=191440 but I don't think that is related because it quit much earlier on and there is no log saved.
*** Bug 191449 has been marked as a duplicate of this bug. ***
It's possible this bug is due VMware. In preparing the VMware hard drive file, there's an option to allocate all the space at once or to have VMWare allocate dynamically. I believe that if it set to allocate all at once, then this situation does not happen. So you may want to cc the Gentoo vmware team and see if they have any feedback and might be of assistance in posting an upstream bug if necessary.
This is obviously not an installer bug. While I do my testing in vmware, we all know it has issues and don't trust failures that occur in it.