[Bio-packaging] Using a shared Guix store (was RE: testing out guix)

[Cook, Malcolm]

Hi Ludovic and Ricardo,

> Ricardo Wurmus <ricardo.wurmus at mdc-berlin.de> skribis:
> 
> > Even then, /gnu would be mounted read-only on all but the management
> > host, because there would still only be one daemon writing to the
> > store and the localstatedir – even if it would take requests from
> > multiple remote guix clients.
> 
> I think $localstatedir (/var/guix by default), or a subset thereof (namely
> /var/guix/profiles/per-user) should be shared read-write over NFS to allow
> users to create the profiles/per-user/$USER symlinks from other machines.

Loduvic, I'm not sure I understand well enough to agree....

Ricardo, I appreciate your fixing my reasoning below....

Certainly per-user profiles must be network readable , since they wind up on PATH.   Perhaps within /gnu/guix/profiles/per-user?

However, if `guix` command is enabled (using ssh/pipe/??) to run in networked environment with build and other work continuing to be coordinated by guix-daemon, then updates to per-user profiles similarly would need to be coordinated.  For example, if a user wants to `guix package --install  somePkg-someVersion` then that package must  be protected against any "simultaneous" garbage collection.  Running the --install through the network daemon is the guix way of protecting against such a race condition.

On this topic, examining the documentation a bit further makes me wonder whether support for `guix build --root  MYROOT` will be impossible when (a) MYROOT is not accessible to the host running guix-daemon.  Will this be an issue?  

Cheers,

Malcolm