Enable logging in the puppet worker (#3411)

This is useful for tests where something is failing :D

polkadot/node/core/pvf/src/lib.rs

@@ -88,6 +88,9 @@ mod worker_common;
 #[doc(hidden)]
 pub mod testing;
 
+#[doc(hidden)]
+pub use sp_tracing;
+
 pub use error::{ValidationError, InvalidCandidate};
 pub use priority::Priority;
 pub use pvf::Pvf;

polkadot/node/core/pvf/src/testing.rs

@@ -50,6 +50,8 @@ pub fn validate_candidate(
 macro_rules! decl_puppet_worker_main {
 	() => {
 		fn main() {
+			$crate::sp_tracing::try_init_simple();
+
 			let args = std::env::args().collect::<Vec<_>>();
 			if args.len() < 2 {
 				panic!("wrong number of arguments");