Looks like that’s the block hash for block 1000 (mainnet). What’s the regtest minimum difficulty? The hash that we don’t want to be found should be something that definitely isn’t possible.
Would also be good to inform the log, for example:
0diff --git a/test/functional/feature_coinstatsindex.py b/test/functional/feature_coinstatsindex.py
1index c6edbe7c31..8e37a3c537 100755
2--- a/test/functional/feature_coinstatsindex.py
3+++ b/test/functional/feature_coinstatsindex.py
4@@ -242,6 +242,7 @@ class CoinStatsIndexTest(BitcoinTestFramework):
5 res12 = index_node.gettxoutsetinfo('muhash')
6 assert_equal(res12, res10)
7
8+ self.log.info("Test obtaining info for a non-existent block hash")
9 assert_raises_rpc_error(-5, "Block not found", index_node.gettxoutsetinfo, hash_type="none", hash_or_height="00000000c937983704a73af28acdec37b049d214adbda81d7e2a3dd146f6ed09", use_index=True)
10
11 def _test_use_index_option(self):