bug#43533: guix-daemon fails to start in Childhurd

[Mathieu Othacehe]

Hello janneke,

>     8ce6f4dc2879919c12bc76a2f4b01200af97e019
>     installer: Run the installation inside a container.
>
> ...but I don't find the commit message quite clear about its intention
> to *always* run guix-daemon in a container; it could be read as
> sugessting to do so only during installation?

Thanks for the detailed bug report. Yes it's not very clear, I'll try to
improve the comments. The idea is that when you run:

herd start guix-daemon PID

then, the guix-daemon joins the given PID namespaces, which is practical
to solve an installation issue.

If guix-daemon is started normally, outside of the installation process,
then it joins the caller namespaces, which should be a no-op. Of course,
it breaks everything if the operating system does not support
namespaces.

Fixed with 6453915cf7729203ef9552c13cb4528c6f4ed122.

Sorry for the breakage,

Mathieu