❯ sudo pacman -Syu
[sudo] password for jkl-pc:
:: Synchronizing package databases...
core is up to date
extra is up to date
multilib is up to date
:: Starting full system upgrade...
resolving dependencies...
looking for conflicting packages...
error: failed to prepare transaction (could not satisfy dependencies)
:: installing boost-libs (1.92.0-1) breaks dependency 'libboost_filesystem.so=1.91.0-64' required by syncthingtray
syncthingtray is an AUR package. That makes you the maintainer on your system. With this particular package, it will need to rebuilt on boost-libs whenever it has a major update with an soname version bump.
Remove syncthingtray temporarily, update your system then rebuild it afterward.
I used to experience something similar virtually every time I performed a sync/update. The main contributor was the maintainer’s inability to release syncthingtray on a schedule to meet the Arch Linux releases of syncthing and supporting packages.
I worked around this by using the Syncthing Tray flatpak instead. Since making that choice I have experienced no further issues.