I am indeed using flash storage, specifically a Samsung Evo 850 (it's a few years old and has had many distress installed and reinstalled on it; now that I'm thinking about it, it wouldn't surprise me at all if this was the underlying issue). I'm trying your recommendation of reinstalling and waiting now. I doubt the installation will finish before I leave for work, so it will certainly sit for at least 5min.

Is there any way that we can verify that the files have finished writing? It seems difficult if the hardware is willing to straight-up lie to us...

On Mon, Jan 21, 2019, 02:16 Danny Milosavljevic <dannym@scratchpost.org wrote:
Hi Ludo,
Hi Bryan,

On Mon, 21 Jan 2019 10:50:41 +0100
Ludovic Courtès <ludo@gnu.org> wrote:

> It’s not surprising to .lock files to be empty.

I agree.  But I didn't filter them out because it would be confusing.

> But where are those
> files you’re talking about?  Surely there’s no /gnu/store on the VFAT
> EFI partition, right?

Oh, these empty files are on the root partition Bryan provided - there
are lots and lots of empty files, including very important ones like the
pam configuration files and the elogind configuration files (which is why
the login didn't work).

It looks like something crashed or sync(2) wasn't called before reboot or
something.

Some flash storage devices like to lie about whether they synced something
(they'll say they did sync but they really didn't yet).  If one then cuts
the power it leads to data loss.  But that's all speculation.

@Bryan: Would you be up to doing the installation again but then before the
reboot do a manual invocation of "sync" and then wait 5 min before rebooting?
Is it flash storage?

I didn't check the contents of the ESP partition because they don't matter.
What matters is whether the ESP partition is dirty (it was) and whether a
manual invocation of "fsck.vfat" succeeds on it (it does).

Out of curiousity I checked ESP anyway now.  It has:

EFI
EFI/GuixSD
EFI/GuixSD/grubx64.efi

$ ls -l EFI/GuixSD/grubx64.efi
-rwxr-xr-x 1 root root 155136 11. Jan 16:52 /mnt/tmp/EFI/GuixSD/grubx64.efi

That's all there is in the ESP partition.