send: log, not println, duplicate message

e2e/tests-dfx/cycles-ledger.bash

@@ -352,8 +352,10 @@ current_time_nanoseconds() {
 
   # same created-at-time: dupe
   assert_command dfx cycles top-up "$(dfx canister id e2e_project_backend)" --created-at-time "$t" 100000 --cycles-ledger-canister-id "$(dfx canister id cycles-ledger)" --identity bob
-  assert_contains "transaction is a duplicate of another transaction in block 3"
-  assert_contains "Transfer sent at block index 3"
+  # shellcheck disable=SC2154
+  assert_contains "transaction is a duplicate of another transaction in block 3" "$stderr"
+  # shellcheck disable=SC2154
+  assert_contains "Transfer sent at block index 3" "$stdout"
   assert_command dfx cycles balance --cycles-ledger-canister-id "$(dfx canister id cycles-ledger)" --precise --identity bob
   assert_eq "2399899900000 cycles."
 

src/dfx/src/commands/cycles/top_up.rs

@@ -53,6 +53,7 @@ pub async fn exec(env: &dyn Environment, opts: TopUpOpts) -> DfxResult {
     let from_subaccount = opts.from_subaccount.map(|x| x.0);
     let result = cycles_ledger::send(
         agent,
+        env.get_logger(),
         to,
         amount,
         created_at_time,

src/dfx/src/lib/operations/cycles_ledger.rs

@@ -113,6 +113,7 @@ pub async fn transfer(
 
 pub async fn send(
     agent: &Agent,
+    logger: &Logger,
     to: Principal,
     amount: u128,
     created_at_time: u64,
@@ -143,9 +144,9 @@ pub async fn send(
         {
             Ok(Ok(block_index)) => Ok(block_index),
             Ok(Err(SendError::Duplicate { duplicate_of })) => {
-                println!(
-                    "transaction is a duplicate of another transaction in block {}",
-                    duplicate_of
+                info!(
+                    logger,
+                    "transaction is a duplicate of another transaction in block {}", duplicate_of
                 );
                 Ok(duplicate_of)
             }