[Nix-dev] [***SPAM***] chroot builds on other Linux platforms

[Michael Raskin]

>I'm using Nix on an "ordinary" Linux distro (not NixOS) and I want to use chroot builds, to make package builds more pure. I've successfully performed a multi-user installation and I've enabled chroot builds in nix.conf. However, the default build-chroot-dirs option value does not include the /bin directory (and therefore also /bin/sh is missing, causing a lot of packages to fail).
>
>I could (of course) add /bin to the build-chroot-dirs option, but this will make the entire /bin folder of my host distro (including a large collection of installed packages binaries) available in the chroot environment, which will still make builds impure, because a lot of packages can be implicitly found.
>
>A possible solution is to bind mount a different directory from my host system (only containing the shell) into the the chroot environment.
>
>I have a dived a bit into the documentation as well as in Nix's source code, but apparently there seems to be no option to specify a source and destination to bind mount an arbitrary directory in the chroot environment, e.g.
>
>mount --bind /my/bin/containing/only/sh/bin /chroot/env/bin
>
>Is there an option to achieve this, or must Nix be extended to do this?

Maybe it is better to bind-mount something as entire / for chroot, and 
then bind-mount Nix store paths? It does seem to work for me on Fedora, 
the chrooting script is included in my configuration helper scripts in
SVN (I do some strange barely-FHS-compliant chroot, though, and chroot 
more from there; /bin/sh is the only thing in /bin and it is a link to 
store).