This test failed a few times recently on CI. It seems like a genuine timeout while trying to mine 1000 blocks:
Traceback (most recent call last): File "/Users/teamcity/buildAgent/work/d82352781e454aab/test/functional/test_framework/test_framework.py", line 142, in main self.run_test() File "/Users/teamcity/buildAgent/work/d82352781e454aab/test/functional/feature_blockfilterindex_prune.py", line 97, in run_test self.generate(node, 1000) [...] test_framework.authproxy.JSONRPCException: 'generatetoaddress' RPC took longer than 30 seconds. Consider using larger timeout for calls that take longer to return. (-344)