You can try rolling back to a previous version though.
By checking the log section in the AUR,
you can see all the commits (changes) done to the build files.
https://aur.archlinux.org/cgit/aur.git/log/?h=util-linux-selinux
Clicking on a commit message shows you the diff.
Start by the last commit,
undo the changes (green lines),
re-apply the removals (red lines),
then attempt to re-build.
If that did not work out,
do the same for the commit before that until you rolled back up to the latest working version.