This works

build.rs

@@ -0,0 +1,15 @@
+include!("src/cli.rs");
+
+use clap::CommandFactory;
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+	let out_dir = std::path::PathBuf::from(
+		std::env::var_os("OUT_DIR").ok_or(std::io::Error::new(std::io::ErrorKind::NotFound, "OUT_DIR not found"))?,
+	);
+	let cmd = Config::command();
+	let man = clap_mangen::Man::new(cmd);
+	let mut buffer: Vec<u8> = Default::default();
+	man.render(&mut buffer)?;
+	std::fs::write(out_dir.join("moq-pub.1"), buffer)?;
+	Ok(())
+}