rust/src/bwrap.rs: check for fuse version

rust/src/bwrap.rs

@@ -15,6 +15,8 @@ use std::os::unix::io::AsRawFd;
 use std::os::unix::process::CommandExt;
 use std::path::Path;
 use std::process::Command;
+use camino::Utf8Path;
+use camino::Utf8PathBuf;
 
 // Links in the rootfs to /usr
 static USR_LINKS: &[&str] = &["lib", "lib32", "lib64", "bin", "sbin"];
@@ -114,6 +116,20 @@ impl RoFilesMount {
     }
 }
 
+fn get_fusermount_path() -> Result<Utf8PathBuf> {
+    let path = std::env::var("PATH").expect("PATH set");
+    let fusermount_binaries = ["fusermount", "fusermount3"];
+    for elt in path.split(':').map(Utf8Path::new) {
+        for bin in fusermount_binaries {
+            let target = elt.join(bin);
+            if target.try_exists()? {
+                return Ok(target);
+            }
+        }
+    }
+    anyhow::bail!("No fusermount path found")
+}
+
 impl Drop for RoFilesMount {
     fn drop(&mut self) {
         let tempdir = if let Some(d) = self.tempdir.take() {
@@ -122,7 +138,7 @@ impl Drop for RoFilesMount {
             return;
         };
         // We need to unmount before letting the tempdir cleanup run.
-        let success = Command::new("fusermount")
+        let success = Command::new(get_fusermount_path().unwrap().to_string())
             .arg("-u")
             .arg(tempdir.path())
             .status()