Use locked_read.

src/module/resolvers/file.rs

@@ -307,12 +307,7 @@ impl FileModuleResolver {
         let file_path = self.get_file_path(path, source_path);
 
         if self.is_cache_enabled() {
-            #[cfg(not(feature = "sync"))]
-            let c = self.cache.borrow();
-            #[cfg(feature = "sync")]
-            let c = self.cache.read().unwrap();
-
-            if let Some(module) = c.get(&file_path) {
+            if let Some(module) = locked_read(&self.cache).get(&file_path) {
                 return Ok(module.clone());
             }
         }

src/module/resolvers/mod.rs

@@ -1,5 +1,5 @@
 use crate::eval::GlobalRuntimeState;
-use crate::func::native::SendSync;
+use crate::func::SendSync;
 use crate::{Engine, Module, Position, RhaiResultOf, Shared, AST};
 #[cfg(feature = "no_std")]
 use std::prelude::v1::*;