Canonical's decision to cease development of 32-bit libraries in Ubuntu 19.10 "eoan" means it won't support Steam gaming runtime and devs say the Wine compatibility layer for running Windows apps will be little use.
The Steam news was reported on Twitter by Valve developer Pierre-Loup Griffais, who said "Ubuntu 19.10 and future releases will not be officially supported by Steam or recommended to our users."
Ubuntu has caused anxiety with its announcement that "the i386 architecture will be dropped" in the next release. Some presumed this meant i386 libraries would not be shipped at all, meaning that no 32-bit applications would run.
This is not the case, as Canonical's Steve Langasek has clarified:
Freezing the libraries may be almost as bad though, from the point of view of Steam, since drivers for new GPUs would be impacted; and Steam without support for the shiniest new GPUs for 32-bit games (of which there are many) would be crippled.
Langasek said last year that "Compatibility with legacy software is important, but it doesn't automatically follow that the right way to provide this compatibility is by continuing to build new versions of the OS for a legacy ABI [Application Binary Interface]. Users who need support for i386 integrated natively into their OS can use Ubuntu 18.04 with security support until April 2023. 18.04 can be run in a chroot or container on top of later Ubuntu releases. 32-bit software distributed as snaps built with an 18.04-derived library runtime can reasonably be expected to work on later releases of Ubuntu for the foreseeable future."
The problem, though, is that the assumption of 32-bit support is deeply woven into a number of applications, the Wine compatibility layer being another.
"Wine heavily relies on i386," said Jens Reyer, co-maintainer of Wine on Debian. "Not only for legacy 32-bit software, but also 'almost all' 64-bit software uses a 32-bit installer ... so although Wine will still be available in the Ubuntu archive on amd64, it'll be basically useless.
"To support current features in new Wine releases you need recent versions of a few libraries (e.g. faudio, vulkan-loader and vkd3d, and those require other recent stuff like sdl2 [Simple Direct Media Layer]
"18.04 is already too old to fully support current Wine with (all) current features. So the solutions proposed like containers and snaps based on 18.04 will not fully work.
"Upstream ... will probably just stop to build for 19.10+. This is not to say that they are not interested in working on a solution."
Canonical could of course change its mind, but if not, it must expect a proportion of users to move to other distributions as a consequence. Worth it for a clean 64-bit slate and lower maintenance costs? Doubtful.®