First, you need to get the Hare compiler. In order to do that grab QBE and scdoc, both of which are packaged for Fedora 42. Now, harec is packaged as well but as of 2026-01-28, it's packaged at v0.24.2, while upstream's latest release is v0.25.2.
Trying to build Hare with v0.24.2 I got an error
HAREC .cache/rt.ssa rt/u64tos.ha:9:39: syntax error: expected ';', found '!' 9 | static append(sl, '0')!; | ^ make: *** [makefiles/linux.x86_64.mk:11: .cache/rt.ssa] Error 3
So, skip the packaged version of harec
sudo dnf install qbe scdoc git clone https://git.sr.ht/~sircmpwn/harec cd harec git checkout v0.25.2 cp configs/linux.mk config.mk && make sudo make install
Now clone and build the Hare compiler
git clone https://git.sr.ht/~sircmpwn/hare cd hare git checkout v0.25.2 cp configs/linux.mk config.mk && make sudo make install
Yay.
git clone https://git.sr.ht/~sircmpwn/himitsu cd himitsu && make sudo make install
Done.
You also need a prompter apparently. Currently, I only know of the gtk one (sad): hiprompt-gtk. Meaning, we need to go and grab all the dependencies to build GTK programs in Hare. Buckle up.
sudo dnf install gobject-introspection gobject-introspection-devel git clone https://git.sr.ht/~yerinalexey/hare-gi cd hare-gi && make sudo make install
sudo dnf install libadwaita libadwaita-devel git clone https://git.sr.ht/~sircmpwn/hare-adwaita cd hare-adwaita && make sudo make install
git clone https://git.sr.ht/~sircmpwn/hare-gtk4-layer-shell
And its at this point I realized: hiprompt-gtk is Wayland only due to requiring gtk4-layer-shell. Well, that sucks. I wonder how usable himitsu is without a GTK/GUI prompter. If it's worthwhile, I'll write my own scripting solution with dmenu or something.