contrib: Fix NameError in signet miner gbt()
What the developer wrote
Authored by Torkel Rogstad
contrib: Fix NameError in signet miner gbt()
The logging.warning call referenced `bci["bestblockhash"]`, a variable
from the calling scope `do_generate()` that is not available inside the
`Generate.gbt()` method. This would crash with a NameError when
getblocktemplate returned a template based on an unexpected previous
block.
Use the `bestblockhash` parameter that was already being passed in and
used correctly in the comparison on the line above.
The bug was introduced in 7b31332370 when the gbt logic was extracted
into its own method — the if-condition was updated but the logging
call was not.
What changed, and why it matters
This is a small bug fix in a helper signet mining script. The script would crash with a NameError when it tried to log a warning about an unexpected previous block, because it referenced a variable that only existed in the calling function. The fix uses the correct variable that was already passed into the method. It is a straightforward coding mistake with no security exploit.
No security action required. Treat as a normal bug fix; merge if the project workflow requires it.
Security signals we found
No security-relevant signals present
Fixes a runtime exception (NameError) in a non-consensus utility script
No input validation, privilege escalation, or cryptographic issues
Evidence from the diff
In contrib/signet/miner, the Generate.gbt() method logged a warning using bci[“bestblockhash”], but bci is not in scope inside gbt(). The correct local parameter bestblockhash was already available and used in the preceding comparison. The patch replaces the dangling reference, preventing a NameError when getblocktemplate returns a template whose previousblockhash differs from the expected best block hash.
Changed components
contrib/signet/minerGenerate.gbt() methodInspect captured patch +1 / −1
diff --git a/contrib/signet/miner b/contrib/signet/miner
index f46d88b5..a7548841 100755
--- a/contrib/signet/miner
+++ b/contrib/signet/miner
@@ -333,7 +333,7 @@ class Generate:
def gbt(self, bcli, bestblockhash, now):
tmpl = json.loads(bcli("getblocktemplate", '{"rules":["signet","segwit"]}'))
if tmpl["previousblockhash"] != bestblockhash:
- logging.warning("GBT based off unexpected block (%s not %s), retrying", tmpl["previousblockhash"], bci["bestblockhash"])
+ logging.warning("GBT based off unexpected block (%s not %s), retrying", tmpl["previousblockhash"], bestblockhash)
time.sleep(1)
return None
Why this scored 19/100
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