Library failure when installing Libsodium (Amazon EC2)

I can't figure out how to get Libsodium up and running on my EC2 instance.

When attempting to check if the installation was successful with:

php7 --info | grep sodium

I get the following warning:

PHP Warning:  PHP Startup: Invalid library (maybe not a PHP library) 'sodium.so' in Unknown on line 0

Here's what I've tried so far:

Installing Libsodium using pecl7 install libsodium.
Installing Libsodium using the latest tar.gz
Reinstalled PHP7 entirely (with apache 2.4)

This particular warning keeps popping up and my sodium functions are still unavailable.

Does anyone have any experience with installing Libsodium on PHP 7(+) on Amazon EC2 instances or do I have to wait for 7.2 to be stable and available?

Edit:

For anyone reading this after this question has been answered: This was a bug in the package manager (https://github.com/jedisct1/libsodium-php/issues/156) the matter has been resolved, reinstalling with pecl7 install libsodium fixed the issues.

Solution

Same on alpine and PHP 7.1... I am installing it via PECL.

There is a bug report about it: https://github.com/jedisct1/libsodium-php/issues/156

You can overcome this issue by forcing to use 2.0.8 until the issue gets fixed: pecl install -f libsodium-2.0.8