Idea: OpenSSL 3.x builds for Gaffer 1.6

[boberfly]

Hi GafferHQ devs,

I was just messing with seeing if OpenSSL 3.x could be used with Rocky 8 builds, and indeed it is possible using the EPEL repo:

sudo dnf install openssl3 openssl3-devel --repo epel

Seeing as though on Windows, Python 3.11 uses OpenSSL 3 it should be a good match:
python/cpython@263d8aa

One caveat at least for CMake projects is that the includes are in a non-standard place eg.

OPENSSL_INCLUDE_DIR=/usr/include/openssl3
OPENSSL_CRYPTO_LIBRARY=/usr/lib64/libcrypto.so.3
OPENSSL_SSL_LIBRARY=/usr/lib64/libssl.so.3

So any other libs (Qt6?) would need this specified so that it finds the right OpenSSL v3 and not v1.1.x. As well as find_package(OpenSSL 3) for CMake projects.

Thoughts? I guess the caveat for Rocky 8 users is they will need openssl3 + openssl3-libs installed, but all distros after have a better time of running and not relying on a backport or compatibility package.

-Alex

[johnhaddon]

In my mind, we'd kindof already spent the dependencies "budget" on the other upgrades for 1.6, and I was happy to be doing some actual development again. So I'm a bit reluctant to be honest. Do you know what other VFXPlatform2024-era DCCs are doing? I suppose if we want to get this for free then it won't happen till VFXPlatform 2026 when we update the build container itself.