Error:
electron: error while loading shared libraries: libre2.so.0: cannot open shared object file: No such file or directory
If you have trouble starting electron based apps like signal-desktop, chromium etc, then try to downgrade re2 from 1:20200303-1 to 1:20200101-1
If you didn't delete you pacman cache since upgrade, you can:
sudo pacman -U /var/cache/pacman/pkg/re2-1:20200101-1-x86_64.pkg.tar.xz
sudo ln -s /usr/lib/libre2.so /usr/lib/libre2.so.0
Works too. Just remember to remove the link after the package maintainer fixed the problem.
electron, chromium, etc. are rebuild with new re2
https://git.archlinux.org/svntogit/community.git/commit/trunk?h=packages/electron&id=b2a4415db31e5c3f9bba524075282842084be4de
https://git.archlinux.org/svntogit/packages.git/commit/trunk?h=packages/chromium&id=a3af1824c6f3c2b0567282b50abff8f7ca13295e