I started from stage 1 tarball after booting from a livecd, built through and including stage 3. I then merged mirrorselect. I ran mirrorselect -i and got a bunch of messages "regular expression error". I found that /etc/make.conf had Gentoomirrors=xxxx where xxx was many lines of what look like ASCII control codes for the shell. I unmerged and merged again - same thing.
I believe duplicate of 16535, 16865. http://bugs.gentoo.org/show_bug.cgi?id=16535 http://bugs.gentoo.org/show_bug.cgi?id=16865
which exact version what this with. Also it shoudl be noted that mirrorselect is NOT to be run while booted from a live cd environment. The issue is with dialog and cannot be fixed. Try running in -a mode. This is a know issue and there is a new version to be coming very soon to the portage tree.
Gone
the pipe/ncurses/livecd problem hasnt been testing in the new version. might or might not be fixed. the updated version (0.3) will fix this problem even if under livecd. mirrorselect -a -s3 -o >> /path/to/make.conf closing bug as fixed :)