Struggling with some ALreadyCalled issues - turning debugging on for the defer module gives some useful insight.

tests/fixtures.py

@@ -31,6 +31,8 @@ import pytest
 from click.testing import CliRunner
 from eth_utils import to_checksum_address
 from sqlalchemy.engine import create_engine
+from twisted.internet import defer
+from twisted.internet.defer import Deferred
 from twisted.logger import Logger
 from web3 import Web3
 
@@ -115,6 +117,7 @@ from umbral.signing import Signer
 
 test_logger = Logger("test-logger")
 
+defer.setDebugging(True)
 
 #
 # Temporary