Nixpkgs: nss lookups on many non-NixOS distros broken after glibc upgrade (whoami: "cannot find name for user ID", openssh (ssh): "no user exists for uid", emacs: "user has no home directory")

[dezgeg]

Issue description

E.g. Arch Linux has this in /etc/nsswitch.conf:
passwd: compat mymachines systemd

... but libnss_compat is no longer included with glibc (it's apparently at https://github.com/thkukuk/libnss_compat instead).

Steps to reproduce

$ nix-build -A coreutils $ ./result/bin/whoami ./result/bin/whoami: cannot find name for user ID 1000

Technical details

• system: "x86_64-linux"
• host os: Linux 4.9.53-1-lts, Arch Linux, noversion
• multi-user?: no
• sandbox: no
• version: nix-env (Nix) 1.11.15
• channels(tmtynkky): "nixpkgs-18.03pre120393.eac38d0b1e"
• nixpkgs: /home/tmtynkky/.nix-defexpr/channels/nixpkgs

[vcunat]

Hmm, it's no longer included, but perhaps we might combine the builds of glibc and libnss_compat into the same set of outputs – then things might work as before.

[dezgeg]

Yup.

Though, now you somehow need to run autoconf on that during bootstrapping...

[dudebout]

One manifestation of this issue is emacs failing to load the user's configuration with the error message:

Error (initialization): User USERNAME has no home directory

(posting this here in case people try to search for this error message)

[greyson]

One-off impure workaround:
export LD_PRELOAD=/usr/lib/libnss_compat.so.2

note, this is probably unstable if nix glibc and arch glibc start to vary too much from eachother.

[dudebout]

If you are not using the compatibility mode offered by nsswitch.conf(5), you can edit /etc/nsswitch.conf and replace compat by files.

[orivej]

035b5892457d7d198090dc6a68cac2b99d2fec52 should fix this when it reaches master. See https://bugs.archlinux.org/task/54592.

[asymmetric]

@orivej What's the easiest way to check when that happens, apart from git branch --contains 035b589 on a clone of the repo?

[orivej]

This issue will be closed then :)
(Now we are waiting for the jobs queued at https://hydra.nixos.org/eval/1412641 to finish in order to merge.)