$ bitcoin-cli --help
Bitcoin Core RPC client version v0.19.0rc1
...
-rpcclienttimeout=<n>
Timeout in seconds during HTTP requests, or 0 for no timeout. (default:
900)
The "0 for no timeout" part, added in #9903, is wrong:
$ time bitcoin-cli -rpcclienttimeout=0 gettxoutsetinfo
error: Could not connect to the server 127.0.0.1:8332 (error code 0 - "timeout reached")
Make sure the bitcoind server is running and that you are connecting to the correct RPC port.
real 0m51.279s
user 0m0.005s
sys 0m0.019s
Both 0.18.0 and 0.19.0rc1 are affected.