MarsSeed [1] filed a deletion request for hdf5-1.12 [2]: Broken, unmaintained, EOL hdf5 package. Conflicts with repo's hdf5, so this kind of PKGBUILD is not allowed on AUR as per submission guidelines.
But also there is absolutely no need to keep this build for any purpose. The experimental API's introduced in 1.12 are now fully supported and mature in HDF5 1.14. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/hdf5-1.12/
