fix watchtower regtest flakiness caused by CTN variability. fixes #7961

electrum/commands.py

@@ -1134,6 +1134,8 @@ class Commands:
                 'remote_pubkey': bh2u(chan.node_id),
                 'local_balance': chan.balance(LOCAL)//1000,
                 'remote_balance': chan.balance(REMOTE)//1000,
+                'local_ctn': chan.get_latest_ctn(LOCAL),
+                'remote_ctn': chan.get_latest_ctn(REMOTE),
                 'local_reserve': chan.config[REMOTE].reserve_sat, # their config has our reserve
                 'remote_reserve': chan.config[LOCAL].reserve_sat,
                 'local_unsettled_sent': chan.balance_tied_up_in_htlcs_by_direction(LOCAL, direction=SENT) // 1000,

electrum/tests/regtest/regtest.sh

@@ -353,14 +353,15 @@ if [[ $1 == "watchtower" ]]; then
     echo "alice pays bob again"
     invoice2=$($bob add_request 0.01 -m "invoice2" | jq -r ".lightning_invoice")
     $alice lnpay $invoice2
+    alice_ctn=$($alice list_channels | jq '.[0].local_ctn')
     msg="waiting until watchtower is synchronized"
-    while watchtower_ctn=$($carol get_watchtower_ctn $channel) && [[ $watchtower_ctn != "3" ]]; do
-        sleep 1
-        msg="$msg."
-        printf "$msg\r"
+    # watchtower needs to be at latest revoked ctn
+    while watchtower_ctn=$($carol get_watchtower_ctn $channel) && [[ $watchtower_ctn != $((alice_ctn-1)) ]]; do
+        sleep 0.1
+        printf "$msg $alice_ctn $watchtower_ctn\r"
     done
     printf "\n"
-    echo "alice and bob do nothing"
+    echo "stopping alice and bob"
     $bob stop
     $alice stop
     ctx_id=$($bitcoin_cli sendrawtransaction $ctx)