Log Only Under STD

Author: Xavier Lau

Cargo.lock

@@ -13,7 +13,6 @@ targets = ["x86_64-unknown-linux-gnu"]
 
 [dependencies]
 codec = { package = "parity-scale-codec", version = "2.0.0", default-features = false }
-log = { version = "0.4.14" }
 mmr-lib = { package = "ckb-merkle-mountain-range", default-features = false, version = "0.3.2" }
 
 sp-core = { version = "4.0.0-dev", default-features = false, path = "../../primitives/core" }

frame/merkle-mountain-range/Cargo.toml

@@ -18,11 +18,11 @@
 //! A MMR storage implementations.
 
 use codec::Encode;
+use frame_support::log;
 use mmr_lib::helper;
 use sp_io::offchain_index;
 #[cfg(not(feature = "std"))]
 use sp_std::prelude::Vec;
-use frame_support::if_std;
 
 use crate::{
 	mmr::{Node, NodeOf},
@@ -122,7 +122,7 @@ where
 		let nodes_to_prune = diff(&peaks_after, &peaks_before);
 		let peaks_to_store = diff(&peaks_before, &peaks_after);
 
-		{
+		sp_std::if_std! {
 			log::trace!("elems: {:?}\n", elems);
 			log::trace!("peaks_before: {:?}", peaks_before);
 			log::trace!("peaks_after: {:?}", peaks_after);