I personally prefer to symlink the folder containing the kernel PKGBUILD
among other files to somewhere else for quicker access and with that
setup .myfrag config fragments were not getting found earlier.
The psi.c compilation error fix was added to the patchset: 53c690361e
I have also added additional compilation fixes for arch_set_thermal_pressure and sched_thermal_decay_shift that I found while working with 5.7RCs. Alfred will likely end up with similar solutions to mine when he fixes it on his end, so it should be pretty transparent.