[Docs] Add a debugging tip: using transaction hashes

docusaurus/docs/develop/developer_guide/debug_tips.md

@@ -16,7 +16,9 @@ If you have a tip you'd like to share with others, please open a PR to add it he
   - [`itest` Example](#itest-example)
   - [TODO: pprof](#todo-pprof)
   - [TODO: dlv](#todo-dlv)
-
+- [`poktrolld query tx` - Investigating Failed Transactions](#poktrolld-query-tx---investigating-failed-transactions)
+  - [`poktrolld query tx` Example](#poktrolld-query-tx-example)
+
 ## `itest` - Investigating Flaky Tests
 
 We developed a tool called `itest` to help with debugging flaky tests. It runs
@@ -39,6 +41,80 @@ test in the `pkg/client/tx` 50 times in total (5 consecutive tests over 10 runs)
 make itest 5 10 ./pkg/client/tx/... -- -run TxClient_SignAndBroadcast_Succeeds
 ```
 
+## `poktrolld query tx` - Investigating Failed Transactions
+
+_tl;dr Submitted Transaction != Committed Transaction_ 
+
+After a transaction (e.g. staking a new service) is successfully sent to an RPC node, we have to wait
+until the next block, when a proposer will try to commit to the network's state, to see if its valid.
+If the transaction's (TX) state transition is invalid, it will not be committed. 
+
+In other words, receiving a transaction (TX) hash from the `poktrolld` CLI doesn't mean it was committed.
+However, the transaction (TX) hash can be used to investigate the failed transaction.
+
+### `poktrolld query tx` Example
+
+The following is an example of `poktrolld query tx` in action to investigate a failed transaction.
+In this example, the command to add a new service is executed as follows, returning the TX hash shown.
+However, the service does not appear in the list of services when querying the full node.
+
+```bash
+poktrolld tx service add-service "svc1" "service1" 1 --from $SUPPLIER_ADDRESS --chain-id=poktroll
+```
+
+The TX hash is returned by the above command:
+
+```bash
+txhash: 9E4CA2B72FCD6F74C771A5B2289CEACED30C2717ABEA4330E12543D3714D322B
+```
+
+To investigate this issue, the following command is used to get the details of the transaction:
+
+```bash
+poktrolld query tx \
+--type=hash 9E4CA2B72FCD6F74C771A5B2289CEACED30C2717ABEA4330E12543D3714D322B \
+--node https://shannon-testnet-grove-seed-rpc.poktroll.com
+```
+
+Which shows the following log entry:
+
+```bash
+info: ""
+logs: []
+raw_log: 'failed to execute message; message index: 0: account has 100000 uPOKT, but
+  the service fee is 1000000000 uPOKT: not enough funds to add service'
+```
+
+The output above shows the cause of the transaction failure: `insufficient funds`. Fixing this by adding
+more funds to the corresponding supplier account will allow the transaction to result in the expected
+state transition.
+
+:::note
+
+If you are reading this and the `9E4CA...` hash is no longer valid, we may have done a re-genesis of 
+TestNet at this point. Please consider updating with a new one!
+
+:::
+
+:::tip
+
+`poktrolld query tx` supports an `--output` flag which can have the values text or json. This can be useful for programatic querying or in combination with tools like `jq`, e.g.:
+
+```bash
+poktrolld query tx \
+--type=hash 9E4CA2B72FCD6F74C771A5B2289CEACED30C2717ABEA4330E12543D3714D322B \
+--node https://shannon-testnet-grove-seed-rpc.poktroll.com \
+ --output json | jq .raw_log
+```
+
+The above command will produce the following output:
+
+```bash
+"failed to execute message; message index: 0: account has 100000 uPOKT, but the service fee is 1000000000 uPOKT: not enough funds to add service"
+```
+
+:::
+
 ### TODO: pprof
 
 ### TODO: dlv