Missing dependency to libtxc-dxtn-s2tc:amd64

[Moritz Oberhauser]

Steam is missing a dependency to libtxc-dxtn-s2tc:amd64

How to reproduce:
- Install steam from the Ubuntu repositories
- Use the mesa drivers
- Download a game that requires GL_EXT_TEXTURE_COMPRESSION_S3TC (e.g. Dota 2)
- Steam throws an error on game start

Workaround:
- Install libtxc-dxtn-s2tc:amd64

https://github.com/ValveSoftware/Dota-2/issues/1213

Release: Ubuntu 17.04
Package: steam:i386 (1:1.0.0.54+repack-2ubuntu5)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[TooManyErrors (toomanyerrors)]

I think this issue would be most easily solved by changing the package libtxc-dxtn-s2tc to be a required dependency for libgl1-mesa-dri rather than just a recommended package.

[Giacomo Orlandi (giaco-orlandi)]

I was stung by this using the Mesa driver.
I concur that it should be a dependency of libgl1-mesa-dri instead of recommended, unless there is some downside to it that I can't see. I'm not a 3d drivers expert.

[Andrew Hayzen (ahayzen)]

Thank you for taking the time to report this bug and helping to make Ubuntu better.

The package libtxc-dxtn-s2tc has been removed from later versions of Ubuntu, therefore I am going to mark this bug as invalid for Steam.