Set a lower threshold for clippy to flag large error variants (#17109)

clippy.toml

@@ -9,4 +9,14 @@ disallowed-types = [
 
 # Lowering the threshold to help prevent stack overflows (default is 16384)
 # See: https://rust-lang.github.io/rust-clippy/master/index.html#/large_futures
-future-size-threshold = 10000
+future-size-threshold = 10000
+
+# Be more aware of large error variants which can impact the "happy path" due
+# to large stack footprint when considering async state machines (default is 128).
+#
+# Value of 70 picked arbitrarily as something less than 100.
+#
+# See:
+# - https://github.com/apache/datafusion/issues/16652
+# - https://rust-lang.github.io/rust-clippy/master/index.html#result_large_err
+large-error-threshold = 70

datafusion/sqllogictest/src/engines/datafusion_engine/error.rs

@@ -28,7 +28,7 @@ pub type Result<T, E = DFSqlLogicTestError> = std::result::Result<T, E>;
 pub enum DFSqlLogicTestError {
     /// Error from sqllogictest-rs
     #[error("SqlLogicTest error(from sqllogictest-rs crate): {0}")]
-    SqlLogicTest(#[from] TestError),
+    SqlLogicTest(#[from] Box<TestError>),
     /// Error from datafusion
     #[error("DataFusion error: {}", .0.strip_backtrace())]
     DataFusion(#[from] DataFusionError),