lsb-release: init at 1.4

[rardiol]

Things done

• Tested using sandboxing (nix-build --option build-use-chroot true or nix.useChroot on NixOS)
• Built on platform(s)
  • NixOS
  • OS X
  • Linux
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.

---

This is the lsb_release executable from https://sourceforge.net/projects/lsb/. Should probably be tested from someone on other linux distro.

Even if nixos is deliberately not LSB-compliant, it seems interesting to include this tool .
Making it useful on nixos requires including a /etc/lsb-release and possibly /etc/nixos-release on nixos.

some potentially relevant discussion and info:

http://www.gossamer-threads.com/lists/gentoo/user/110551

http://linux.die.net/man/1/lsb_release

cc @grahamc

[abbradar]

FWIW I was attracted by a thought "lsb-release? What? NixOS is not compliant by any means!" but the manual page explicitly has an example of what happens when distribution is not LSB-compatible, so this utility is useful anyway. If I understand correctly, for this to work we would need to have /etc/nixos-release (but no /etc/lsb-release) with some constants defined. Seems OK to me (would simplify detection of us by various scripts, because /etc/*-release file is a de facto standard).

[joachifm]

Hm, nixpkgs users might want this, regardless of nixos.
(EDIT: so adding lsb-release support to NixOS is a separate issue, IMO)

[abbradar]

Fair enough.

[vcunat]

We do have /etc/os-release on NixOS, but the utility doesn't pick it up:

$ ./result/bin/lsb_release -a
LSB Version:    n/a
Distributor ID: n/a
Description:    (none)
Release:        n/a
Codename:       n/a

But I agree that's a separate issue.

[abbradar]

After adding /etc/nixos-release with this text:

NixOS release 16.09.git.56a2384 (Flounder)

It reports:

 nixpkgs git:(master) ✗ result/bin/lsb_release -a
LSB Version:    n/a
Distributor ID: NixOS
Description:    NixOS release 16.09.git.56a2384 (Flounder)
Release:    16.09.git.56a2384
Codename:   Flounder

From what I understand, /etc/os-release is a separate standard by Freedesktop.org sigh. Also we have /etc/NIXOS, empty one.

[abbradar]

@edolstra do you think it would be useful for us to add /etc/nixos-release to make us discoverable by lsb-release utility (as a non-LSB-compatible distribution)? (asking you because this falls into "core decision" of some kind in my head, albeit a small one) FWIW I don't know of anyone relying on LSB, but I suppose it can be popular in the enterprise world (which I haven't tapped into).

[rardiol]

Note that we don't need to use this specific lsb_release executable if an alternate one that reads /etc/os-release is better.

[abbradar]

Oh, indeed... if there is just a version which can parse os-release and is compatible, it would be ideal.

Also lsb_release is not compatible with os-release and it works for us purely by chance because nixos-release is the first file that it finds. Try using it for znixos-release.

[vcunat]

Sticking (more closely) to the published (freedesktop) standards is probably better than patching the tools, even if the standards are kinda ad hoc...

[abbradar]

The problem is that there are two of them (FreeDesktop and lsb_release documentation "standard"), and they are incompatible if I understood correctly D: By "incompatible" I mean that FreeDesktop proposes /etc/os-release and lsb_release(1) expects to find /etc/lsb-release or /etc/*-release for non-LSB-compatible distributions. When it picks /etc/os-release it fails to parse it, and my example above was purely by luck: /etc/nixos-release was returned first by find, looking at the utility's source.