Specifically, if we're not root and the daemon socket does not exist,
then we use ~/.local/share/nix/root as a chroot store. This enables
non-root users to download nix-static and have it work out of the box,
e.g.
ubuntu@ip-10-13-1-146:~$ ~/nix run nixpkgs#hello
warning: '/nix' does not exists, so Nix will use '/home/ubuntu/.local/share/nix/root' as a chroot store
Hello, world!
With this, Nix will write a copy of the sandbox shell to /bin/sh in
the sandbox rather than bind-mounting it from the host filesystem.
This makes /bin/sh work out of the box with nix-static, i.e. you no
longer get
/nix/store/qa36xhc5gpf42l3z1a8m1lysi40l9p7s-bootstrap-stage4-stdenv-linux/setup: ./configure: /bin/sh: bad interpreter: No such file or directory
Useful because a default `sudo` on darwin doesn't clear `$HOME`, so things like `sudo nix-channel --list`
will surprisingly return the USER'S channels, rather than `root`'s.
Other counterintuitive outcomes can be seen in this PR description:
https://github.com/NixOS/nix/pull/6622
Overrides for inputs with flake=false were non-sticky, since they
changed the `original` in `flake.lock`. This fixes it, by using the same
locked original for both flake and non-flake inputs.
nixos/nix#6290 introduced a regex pattern to account for tags when
resolving sourcehut refs. nixos/nix#4638 reafactored the code,
accidentally treating the pattern as a regular string, causing all
non-HEAD ref resolving to break.
This fixes the regression and adds more test cases to avoid future
breakage.
The manpage for `getgrouplist` says:
> If the number of groups of which user is a member is less than or
> equal to *ngroups, then the value *ngroups is returned.
>
> If the user is a member of more than *ngroups groups, then
> getgrouplist() returns -1. In this case, the value returned in
> *ngroups can be used to resize the buffer passed to a further
> call getgrouplist().
In our original code, however, we allocated a list of size `10` and, if
`getgrouplist` returned `-1` threw an exception. In practice, this
caused the code to fail for any user belonging to more than 10 groups.
While unusual for single-user systems, large companies commonly have a
huge number of POSIX groups users belong to, causing this issue to crop
up and make multi-user Nix unusable in such settings.
The fix is relatively simple, when `getgrouplist` fails, it stores the
real number of GIDs in `ngroups`, so we must resize our list and retry.
Only then, if it errors once more, we can raise an exception.
This should be backported to, at least, 2.9.x.
