Allow overriding udevd binary path at runtime

Signed-off-by: Val Packett <[email protected]>

Author: valpackett

crates/muvm/src/guest/bin/muvm-guest.rs

@@ -77,9 +77,16 @@ fn main() -> Result<ExitCode> {
     rustix::stdio::dup2_stdout(console.as_fd())?;
     rustix::stdio::dup2_stderr(console.as_fd())?;
 
-    Command::new(std::option_env!("MUVM_UDEVD_PATH").unwrap_or("/usr/lib/systemd/systemd-udevd"))
-        .spawn()
-        .context("Running systemd-udevd")?;
+    const DEFAULT_UDEVD_PATH: &str = match std::option_env!("MUVM_UDEVD_PATH") {
+        Some(path) => path,
+        None => "/usr/lib/systemd/systemd-udevd",
+    };
+    Command::new(
+        env::var("MUVM_UDEVD_PATH").unwrap_or_else(|_| DEFAULT_UDEVD_PATH.parse().unwrap()),
+    )
+    .spawn()
+    .context("Failed to execute `systemd-udevd` as a child process")?;
+    env::remove_var("MUVM_UDEVD_PATH");
 
     if let Some(emulator) = options.emulator {
         match emulator {