Support lifecycle for older distributions
We currently package for Debian 8 (Jessie) from 2015, and Ubuntu 16.04; this constrains us in several ways, such as:
- supporting building with older system libraries, especially OpenSSL 1.0 (1.1+ includes many breaking changes)
- supporting older GCC versions, runtimes, and C++ ABIs
- maintaining internal test infrastructure for these old distributions
To allow more time to be spent on improving Hack itself, in the future, we will be more aggressive about removing support for older distributions.
HHVM 4.32 - due to be announced later today - will be an LTS release; 4.56 will be the next LTS release, and is due in 24 weeks (week of 2020-05-04). 4.56 will be the last release that supports:
- MacOS Mojave
- Debian 8 Jessie
- Debian 9 Stretch
- Ubuntu 16.04
In HHVM 4.57 and above, we will aim to support:
- MacOS: the latest stable release (currently Catalina). If the release has been stable for less than 6 months, we will also aim to support the previous stable version (currently Mojave)
stable(currently Buster). If the current
stablewas released in the last 6 months, we will also aim to support
oldstable(currently Stretch). We are open to investigating support for Debian
testing(currently Bullseye), but are not currently doing so.
- the current LTS release (18.04); if the LTS is less than 6 months old, the previous LTS will also be supported
- non-LTS (‘interim’) releases will be supported for 9 months from their release; this matches the length of time that they are supported by Canonical
What ending support means
In general, we do not intend to proactively stop testing/packaging for distributions as soon as they become ‘unsupported’; however:
- when we want to upgrade our internal test infrastructure or update the minimum versions of our dependencies, the versions provided by unsupported distributions will not be a factor in that decision
- if our packaging starts failing on supported distributions, we may stop building for them instead of fixing it
Given we want to remove support for OpenSSL 1.0 and for systems using the C++5 ABI, we expect to stop building packages for several distributions - especially Debian 8 Jessie and Ubuntu 16.04 very shortly after the release of HHVM 4.56.
Bugfix and security updates
If we build a package for a distribution for a x.y.0 release, we intend to build packages for that distribution for any x.y.z releases - as long as the distribution itself continues to receive security updates from the distribution vendor.
In other words, dropping support for a distribution in a new release does not affect support for that distribution in past verisons of HHVM.
- 4.56.0 will support Debian 8 Jessie and Ubuntu 16.04
- if a 4.56.1 release is made mid-June 2020, it would still support Debian 8 and Ubuntu 16.04 - even if 4.57 has been released without support for those distributions
- if a 4.56.2 release is made in July 2020, it would still support Ubuntu 16.04, but it would not support Debian 8, as Debian 8 reaches end of life on June 30th, 2020
Using unsupported distributions
We strongly recommend using a supported distribution instead. That said, there are several options:
- run HHVM via Docker or other containerization techniques
- install/build updated versions of any required dependencies (likely to include GCC and OpenSSL), then build/package HHVM yourself
- send pull requests to fix builds on unsupported distributions - though we will not accept pull requests that increase the burden on developers; for example, once folly drops support for OpenSSL 1.0, we will not accept pull requests that re-add it
If you are using a current version of a distribution that we do not package for at all (e.g. CentOS), we would appreciate pull requests to add support to our packaging infrastructure; any new packaging should be:
- reproducible. For example, fetching
masterof a dependency from github is not acceptable
- following the distribution’s best practices for packaging as much as possible.
For example, this could mean using
debuildor similiar instead of manually building a package from binaries created separately
The HHVM support lifecycle for any other distributions would likely be similar to our support lifecycle for Debian and Ubuntu, aiming to provide some upgrade window while allowing us to frequently update the minimum versions of dependencies.