The perl package now uses a versioned path for compiled modules. This means that modules built for a non-matching perl version will not be loaded any more and must be rebuilt.
A pacman hook warns about affected modules during the upgrade by showing output like this:
WARNING: '/usr/lib/perl5/vendor_perl' contains data from at least 143 packages which will NOT be used by the installed perl interpreter.
-> Run the following command to get a list of affected packages: pacman -Qqo '/usr/lib/perl5/vendor_perl'
You must rebuild all affected packages against the new perl package before you can use them again. The change also affects modules installed directly via CPAN. Rebuilding will also be necessary again with future major perl updates like 5.28 and 5.30.
Please note that rebuilding was already required for major updates prior to this change, however now perl will no longer try to load the modules and then fail in strange ways.
If the build system of some software does not detect the change automatically, you can use
perl -V:vendorarch in your PKGBUILD to query perl for the correct path. There is also
sitearch for software that is not packaged with pacman.
Specifically the newest Linux-libre kernel
$ sudo pacman -S parabola-keyring
$ sudo pacman-key --refresh-keys
Due to a little boondoggle, some users may have trouble upgrading
mesa because pacman can't figure out the dependency tree. If this is the case, and pacman tells you that it can't satisfy dependencies on
mesa-libgl, then you should be able to resolve this by manually telling pacman that the resolution is
# pacman -Su libglvnd
Additionally, multilib users may need to manually downgrade from the no-longer-existing
libre-multilib/lib32-mesa and friends to
multilib/lib32-mesa and friends.
The upgrade to ca-certificates-utils 20170307-1 requires manual intervention because a symlink which used to be generated post-install has been moved into the package proper.
As deleting the symlink may leave you unable to download packages, perform this upgrade in three steps:
# pacman -Syuw # download packages
# rm /etc/ssl/certs/ca-certificates.crt # remove conflicting file
# pacman -Su # perform upgrade
Due to outstanding privacy and freedom violations in Chromium, qt5-webengine and popcorntime have been removed. We will make our best effort to find replacements and patch any affected software. Please see our announcement on the mailing list following recommendation from Mr. Stallman.