I'm trying to install libsodium (following this guide https://paragonie.com/book/pecl-libsodium/read/00-intro.md#installing-libsodium). When I attempt to use pecl install libsodium, I get the following result:
Build process completed successfully
Installing '/usr/lib/php/extensions/no-debug-non-zts-20121212/libsodium.so'
ERROR: failed to write /usr/lib/php/extensions/no-debug-non-zts-20121212/libsodium.so (copy(/usr/lib/php/extensions/no-debug-non-zts-20121212/libsodium.so): failed to open stream: Operation not permitted)
Can anyone tell me why this isn't working, and how I can overcome it?