diff --git a/crates/moonbuild/src/gen/gen_build.rs b/crates/moonbuild/src/gen/gen_build.rs
index d6322842..11c92e15 100644
--- a/crates/moonbuild/src/gen/gen_build.rs
+++ b/crates/moonbuild/src/gen/gen_build.rs
@@ -505,6 +505,12 @@ pub fn gen_n2_build_state(
                 .to_string();
 
             let bin_script_path = install_path.join(bin_script_name);
+            if bin_script_path.exists() && bin_script_path.is_dir() {
+                anyhow::bail!(
+                    "bin install failed, there is a directory {:?} already exists",
+                    bin_script_path
+                );
+            }
 
             if !bin_script_path.exists() {
                 let artifact_output_path = PathBuf::from(&item.out)
diff --git a/crates/moonbuild/src/pre_build.rs b/crates/moonbuild/src/pre_build.rs
index d5f3b4b8..eb12895a 100644
--- a/crates/moonbuild/src/pre_build.rs
+++ b/crates/moonbuild/src/pre_build.rs
@@ -126,8 +126,8 @@ pub fn load_moon_pre_build(
                         .source_dir
                         .join(maybe_ps1)
                         .with_extension("ps1");
-                    let ps1_path = dunce::canonicalize(ps1_path).unwrap();
                     if ps1_path.exists() {
+                        let ps1_path = dunce::canonicalize(ps1_path).unwrap();
                         format!("powershell {}", ps1_path.display())
                     } else {
                         command