fix missing import when chronicles enabled

nimbus/nimbus.nim

@@ -162,6 +162,7 @@ proc process*(nimbus: NimbusNode) =
       poll()
     except CatchableError as e:
       debug "Exception in poll()", exc = e.name, err = e.msg
+      discard e # silence warning when chronicles not activated
 
   # Stop loop
   waitFor nimbus.stop()

nimbus/p2p/chain.nim

@@ -1,6 +1,6 @@
 import ../db/db_chain, eth/common, chronicles, ../vm_state, ../vm_types,
   ../vm/[computation, message], ../vm/interpreter/vm_forks, stint, nimcrypto,
-  ../utils, eth/trie/db, ../tracer, ./executor, ../config, ../genesis, ../utils,
+  ../utils, eth/trie/db, ./executor, ../config, ../genesis, ../utils,
   stew/endians2
 
 type

nimbus/vm/computation.nim

@@ -14,6 +14,9 @@ import
   ../utils/header, precompiles,
   transaction_tracer, ../utils
 
+when defined(chronicles_log_level):
+  import stew/byteutils
+
 when defined(evmc_enabled):
   import evmc/evmc, evmc_helpers, evmc_api, stew/ranges/ptr_arith