While this behaviour is likely intended, and generally fine, it does lead to unintuitive side effects for new prefix users. Specifically, systemwide customizations to HISTSIZE and HISTFILESIZE are ignored, which leads anyone using the startprefix script to overwrite and destroy their history file. The simplest solution would be to copy /etc/bash/* to $EPREFIX/etc/bash, but failing that, a warning in the eprefix install script would be prudent.
this behaviour is indeed very intended, and necessary for proper operation also I'm not sure if users are actually very aware of what's in their host-provided bashrc files, but do you think a warning with some examples would suffice here?
I think you're likely correct that many users are unaware of the contents (or the existence) of the systemwide bashrc files. It's most likely to cause problems when a sysadmin customizes the systemwide bashrc. The prefix shell then ignores the systemwide files, which can cause subtle (or not so subtle) breakages. I think a note in the auto installer script saying that if you have system wide bashrc stuff you should do something intelligent would suffice. I don't think we can programatically determine what 'intelligent' is, especially since we want to support non gentoo host systems. Some users might want to specify a prefix specific HISTFILE, some might want to just copy their host bashrc files, some might not care. Just letting people know not to run the prefix bash before resolving any issues would probably be enough. As for where in the auto installer to put the message... The actual damage comes from running the startprefix script, so the startscript target of the bootstrap script may be a good target. The introductory text and interactive mode would also be a good target. A slightly more ambitious goal would be to ask the user in interactive mode for any scripts to drop in the prefix, but that would require more careful thought and checking than just adding a few examples and a warning.
Also, I think a note should get added to the gentoo wiki article on the bootstrap script, but I lack the permissions to edit that page.
