improve error message

Author: paketb0te

src/_bcrypt/src/lib.rs

@@ -78,14 +78,14 @@ fn hashpw<'p>(
     // bytes on the updated prefix $2b$, but leaving $2a$ unchanged for
     // compatibility. However, pyca/bcrypt 2.0.0 *did* correctly truncate inputs
     // on $2a$, so we do it here to preserve compatibility with 2.0.0
-    // Silent truncation is _probably_ not the best idea, even if the "original" 
+    // Silent truncation is _probably_ not the best idea, even if the "original"
     // OpenBSD implementation did/does this.
     // We prefer to raise a ValueError in this case - if the user _wants_ to truncate,
     // they can always do so manually by passing s[:72] instead of s into hashpw().
 
     if password.len() > 72 {
         return Err(pyo3::exceptions::PyValueError::new_err(
-            "Password cannot be longer than 72 bytes",
+            "password cannot be longer than 72 bytes, truncate manually if necessary (e.g. my_password[:72])",
         ));
     }