[arch-general] race condition when upgrading the new ncurses package

[Martti Kühne]

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