I had these messages for the readline update in question, too. I think it's just natural that if ncurses is a dep of readline and readline is a dep of bash, that bash would link the ncurses.so it was built against. During the update, readline's post-upgrade install-snippet can't be run with bash, because bash links it and its own dependency ncurses, which, as a dependency, is already upgraded to provide the newest version. To have a fully up to date info directory, it appears, the install-info updates that are attempted for readline need to be executed by hand after running pacman -Syu. All this is obvious if you look at the install file you should have in /var/abs/*/readline/ and basic knowledge about how archlinux packages work. In fact, I guess it's sort of a logical requirement to using archlinux to catch these things, because, as is denoted in the wiki, partial updates are unsupported [0] and your system forcefully goes through partially updated state during an update... cheers! mar77i [0] https://wiki.archlinux.org/index.php/Pacman#Partial_upgrades_are_unsupported
