The next release of pacman (after pacman 5.1.3-1.3) will set the architecture to "pentium4" if you have
in your /etc/pacman.conf and your machine supports sse2 instructions.
This requires reinstallation (and if necessary a downgrade) of all installed packages, e.g. by running
pacman -Qqn | pacman -S -
Note, that this is only possible and necessary after pacman > 5.1.3-1.3 gets installed.
Also note, that it's not a good idea to stick with i686 if your machine supports sse2, as more and more packages require sse2 and will be dropped from the i686 repositories, thus.
Edit: There seems to be a flaw in the sse2 detection logic of pacman 5.1.3-1.4 - it correctly switches to pentium4 on my test vm, but not on my test real hardware (both with sse2). You can check with
if it changes to pentium4 for you - and apply the above steps only if it does so.
I'm working on it ... stay tuned.
A new architecture is available, called 'pentium4'. This one is for CPUs supporting at least SSE2.
For installation and transition information head to:
Installation of pentium4 optimized packages
libreadline 8 made it into [core], although not all packages were rebuilt against it yet.
This breaks several packages, some of them vital for the system.
Before proceeding to update, please check the package database for the updated packages if it mentions a 'not satisfiable dependency: "libreadline.so.7"'.
I'll update this notice when all/most packages have been rebuilt against the new readline package and have been moved to core/extra/community.
Sorry for the trouble,
most packages have been rebuilt and are in core/extra/community. Exceptions:
It seems, I managed to break several packages by updating icu. The current list (known to our database / me) is:
i686/community/0ad-a23-4.0-i686 (0ad-a23-6.0-i686 now available in [community])
i686/community/aegisub-3.2.2-28.0-i686 (aegisub-3.2.2-30.0-i686 now available in [community])
i686/community/calibre-3.31.0-1.0-i686 (calibre-3.34.0-1.0-i686 now available in [community])
i686/community/haskell-hakyll-220.127.116.11-117.0-i686 (haskell-hakyll-18.104.22.168-67.0-i686 now available in [community])
i686/community/kbibtex-1:0.8.1-2.1-i686 (kbibtex-1:0.8.1-3.0-i686 now available in [community])
i686/community/pandoc-citeproc-0.14.3.1-133.0-i686 (pandoc-citeproc-0.14.8.1-1.0-i686 now available in [community])
i686/community/scribus-1.5.4-1.0-i686 (scribus-1.5.4-5.0-i686 now available in [community])
i686/extra/chromium-69.0.3497.92-1.0-i686 (chromium-70.0.3538.77-2.0-i686 now available in [extra])
i686/extra/firefox-62.0-1-i686 (firefox-63.0.3-1.0-i686 now available in [extra])
i686/extra/libreoffice-fresh-6.1.1-1.0-i686 (libreoffice-fresh-6.1.3-1.0-i686 now available in [extra])
i686/extra/libreoffice-still-6.0.6-3.0-i686 (libreoffice-still-6.0.7-1.0-i686 now available in [extra])
i686/extra/mpd-0.20.21-1.0-i686 (mpd-0.21.1-1.0-i686 now available in [extra])
i686/extra/thunderbird-60.0-4-i686 (thunderbird-60.3.1-2.0-i686 now available in [extra])
If you require any of those packages (or packages which depend on those), please postpone updates, until we rebuilt those packages.