Ensure make uses bash as its shell The upstream Makefile contains several bash constructs (like '[['). These fail on debian because the default shell for make is /bin/sh which points to dash. And dash does not support such constructs. So have make use /bin/bash as its shell.
Use system version of udis86 Hyprland sources are shipped with a copy of udis86, against which the binaries are built. We will instead build against the Debian version of the library.
Use system version of hyprland-protocols Hyprland sources include a copy of hyprland-protocols. We will, instead, use the system version of this package.
Add FORTIFY_SOURCE flag directly in Makefile The flag, otherwise, doesn't seem to propogate correctly to all modules built by the project. Use 'checksec' and 'hardening-check' for verifying fortification on binaries.