dwm is not in Java's internal list of non-reparrenting
window managers. Running Java GUI programs without this
variable on window managers (eg. jd-gui) causes the window
to be blank.
conversions were done using https://github.com/pennae/nix-doc-munge
using (probably) rev f34e145 running
nix-doc-munge nixos/**/*.nix
nix-doc-munge --import nixos/**/*.nix
the tool ensures that only changes that could affect the generated
manual *but don't* are committed, other changes require manual review
and are discarded.
