Install the CLI with an overwriting symbolic link.

crates/bds-cli/src/lib.rs

@@ -1859,11 +1859,15 @@ mod tests {
         assert!(fixture.run(&["install"], "").is_err());
     }
 
+    #[cfg(unix)]
     #[test]
-    fn launcher_install_is_idempotent_and_refuses_overwrite() {
+    fn launcher_install_is_idempotent_and_overwrites_existing_file() {
         let fixture = Fixture::new(false);
         let executable = fixture._root.path().join("packaged-bds-cli");
         std::fs::write(&executable, b"binary").unwrap();
+        let target = fixture.home_dir.join(".local/bin/bds-cli");
+        std::fs::create_dir_all(target.parent().unwrap()).unwrap();
+        std::fs::write(&target, b"old launcher").unwrap();
         let context = RunContext {
             executable_path: executable.clone(),
             ..fixture.context("")
@@ -1878,12 +1882,10 @@ mod tests {
             context,
         )
         .unwrap();
-        let target = fixture.home_dir.join(".local/bin/bds-cli");
-        assert!(!target.is_symlink());
-        assert!(
-            std::fs::read_to_string(target)
-                .unwrap()
-                .contains(executable.canonicalize().unwrap().to_str().unwrap())
+        assert!(target.is_symlink());
+        assert_eq!(
+            std::fs::read_link(target).unwrap(),
+            executable.canonicalize().unwrap()
         );
     }
 }