Use clang instead of gcc, which seems easier to install.

src/backend/eval.rs

@@ -52,11 +52,10 @@ impl Backend<ObjectModule> {
         }
     }
 
-    #[cfg(target_family = "unix")]
     fn link(object_file: &Path, executable_path: &Path) -> Result<(), EvalError> {
-        use std::{os::unix::prelude::PermissionsExt, path::PathBuf};
+        use std::path::PathBuf;
 
-        let output = std::process::Command::new("gcc")
+        let output = std::process::Command::new("clang")
             .arg(
                 PathBuf::from(env!("CARGO_MANIFEST_DIR"))
                     .join("runtime")
@@ -67,16 +66,13 @@ impl Backend<ObjectModule> {
             .arg(executable_path)
             .output()?;
 
-        if output.stderr.is_empty() {
+        if !output.stderr.is_empty() {
-            let mut perms = std::fs::metadata(executable_path)?.permissions();
+            return Err(EvalError::IO(
-            perms.set_mode(perms.mode() | 0o100); // user execute bit
-            std::fs::set_permissions(executable_path, perms)?;
-            Ok(())
-        } else {
-            Err(EvalError::IO(
                 std::string::String::from_utf8_lossy(&output.stderr).to_string(),
-            ))
+            ));
         }
+
+        Ok(())
     }
 }