Okay then. That doesn't seem to exist in all configs.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "dukbind"
-version = "0.0.3"
+version = "0.0.4"
 authors = ["envis10n <envis10n@protonmail.com>"]
 edition = "2018"
 build = "build.rs"

src/lib.rs

@@ -38,14 +38,6 @@ extern "C" {
         message: *const i8) -> duk_idx_t;
 }
 
-extern "C" {
-    /// Returns 1 if value at idx inherits from Error, otherwise returns 0. If idx is invalid, also returns 0.
-    pub fn duk_is_error(
-        ctx: *mut duk_context,
-        idx: duk_idx_t
-    ) -> duk_bool_t;
-}
-
 #[cfg(test)]
 mod tests {
     #[test]