[Seeking Volunteers] Add new builds to CacheLib

[therealgymmy]

Hi, we're looking for volunteers to add support for newer build platforms such as Ubuntu 24.04 and Debian 12.

You will need to add support for new platforms in https://github.com/facebook/CacheLib/tree/main/contrib

For example, prerequisite for ubuntu 22 is the same as ubuntu 18 (https://github.com/facebook/CacheLib/blob/main/contrib/build.sh#L166), which is specified by https://github.com/facebook/CacheLib/blob/main/contrib/prerequisites-ubuntu18.sh.

[vaavaav]

Hi! I would like to help as best as I can.
Do you have a list of all the platforms planned to support CacheLib?

[haowu14]

Hi @vaavaav thanks for reaching out.
We hope we can have support for ubuntu 24 and the latest Fedora at least. The expectation would be you can create a script like this (https://github.com/facebook/CacheLib/blob/main/contrib/prerequisites-ubuntu18.sh), and wire it up into the main build script (https://github.com/facebook/CacheLib/blob/main/contrib/build.sh).

Then cachelib team will create a github action to run it.

[vaavaav]

@haowu14

I wanted to share my findings and get an opinion regarding a compatibility issue.

I successfully built CacheLib (using the most stable release, v20240320_stable) on Ubuntu 24.04 and 22.04. However, building on Ubuntu 18.04 and 20.04 fails due to a dependency issue with Folly.

I gathered that Folly requires at least g++-11 to compile: facebook/folly#1444 (comment) (be aware that this might not be completely true). Unfortunately, on Ubuntu 18.04 and 20.04, there isn't a straightforward way to install g++-11 using standard methods (e.g., a simple apt-get install).

The workaround I found involves:

# Ensure software-properties-common is installed
sudo apt-get update
sudo apt-get install -y software-properties-common

# Add the required repository for newer GCC versions
sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt-get update

# Install g++-11
sudo apt-get install -y g++-11

# Update the alternatives to use g++-11
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-11 100
sudo update-alternatives --config g++

Is this approach too intrusive to include directly in prerequisites-ubuntu18.sh?