Nginx+Passenger Error - libcurl.so.4: version `CURL_OPENSSL_3' not found

Question

System:

• Ubuntu: 18.04 LTS
• Passenger: 5.3.1
• nginx with libnginx-mod-http-passenger

$ sudo nginx -t

Returns:

PassengerLoggingAgent: /usr/lib/x86_64-linux-gnu/libcurl.so.4: version `CURL_OPENSSL_3' not found (required by PassengerLoggingAgent)
2018/06/04 02:28:40 [alert] 10411#0: Unable to start the Phusion Passenger watchdog because it encountered the following error during startup: Unable to start the Phusion Passenger logging agent: it seems to have crashed during startup for an unknown reason, with exit code 1 (-1: Unknown error)

```

Answer 1

You can install the required version 3 from the bionic repository if you don't depend on other software that already uses version 4:

sudo apt install libcurl3/bionic

This will ask you to remove curl itself, libcurl4, and dependend software. Consider carefully if you need those, before removing them.

You still can roll back by installing libcurl4 and the removed software again.

Answer 2

This fixed my problem:

sudo apt install libcurl4-openssl-dev