bug#21209: /gnu/store should be able to be a symlink, but it can't

bug#21209: /gnu/store should be able to be a symlink, but it can't

[Kragen Javier Sitaker]

Apparently I can’t make /gnu/store a symlink:

    : user@debian:~/pkgs/guix-0.8.1; time /usr/local/bin/guix pull
    guix pull: error: build failed: `/gnu/store' is not a directory

    real	0m0.431s
    user	0m0.104s
    sys	0m0.036s
    : user@debian:~/pkgs/guix-0.8.1; ls -l /gnu/store
    lrwxrwxrwx 1 root root 9 Aug  7 12:56 /gnu/store -> /gnustore
    : user@debian:~/pkgs/guix-0.8.1; ls -Ldl /gnu/store
    drwxrwxr-t 40 root guix-builder 49152 Aug  7 12:56 /gnu/store

Is there a reason for this?  It’s inconvenient.  (My root SSD only has
a couple gigs left.)

I’m working around that by directly mounting the /gnustore partition
under /gnu/store now.

    : user@debian:~/pkgs/guix-0.8.1; sudo vi /etc/fstab
    : user@debian:~/pkgs/guix-0.8.1; grep store /etc/fstab
    /tb/gnustore.ext4 /gnu/store     ext4    loop            2       3
    : user@debian:~/pkgs/guix-0.8.1; sudo umount /gnustore
    : user@debian:~/pkgs/guix-0.8.1; sudo rm /gnu/store
    : user@debian:~/pkgs/guix-0.8.1; sudo mkdir /gnu/store
    : user@debian:~/pkgs/guix-0.8.1; sudo mount -a

bug#21209: /gnu/store should be able to be a symlink, but it can't

[Claes Wallin]

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Not commenting on the underlying problem, but on your workaround.

On 07-Aug-2015 11:22 pm, "Kragen Javier Sitaker" <kragen@canonical.org>
wrote:
>
> Apparently I can’t make /gnu/store a symlink:

[ . . . ]

> I’m working around that by directly mounting the /gnustore partition
> under /gnu/store now.

[ . . . ]

>     /tb/gnustore.ext4 /gnu/store     ext4    loop            2       3

You don't need to make a new file system and a loop mount. You could just
make a bind mount.

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bug#21209: /gnu/store should be able to be a symlink, but it can't

[Pjotr Prins]

it is by design that you can't symlink.

On Sat, Aug 08, 2015 at 06:51:17AM +0200, Claes Wallin wrote:
>    Not commenting on the underlying problem, but on your workaround.
> 
>    On 07-Aug-2015 11:22 pm, "Kragen Javier Sitaker" <[1]kragen@canonical.org>
>    wrote:
>    >
>    > Apparently I can’t make /gnu/store a symlink:
> 
>    [ . . . ]
> 
>    > I’m working around that by directly mounting the /gnustore partition
>    > under /gnu/store now.
> 
>    [ . . . ]
> 
>    >     /tb/gnustore.ext4 /gnu/store     ext4    loop            2       3
> 
>    You don't need to make a new file system and a loop mount. You could just
>    make a bind mount.
> 
> References
> 
>    Visible links
>    1. mailto:kragen@canonical.org

-- 

bug#21209: /gnu/store should be able to be a symlink, but it can't

[Kragen Javier Sitaker]

On Sat, Aug 08, 2015 at 11:31:19AM +0200, Pjotr Prins wrote:
> it is by design that you can't symlink.

If that is true (and it seems like a rather strange design; why would somebody
want that?) I think that the error message should explain that rather than
simply complaining that /gnu/store is "not a directory".

> On Sat, Aug 08, 2015 at 06:51:17AM +0200, Claes Wallin wrote:
> >    On 07-Aug-2015 11:22 pm, "Kragen Javier Sitaker" <[1]kragen@canonical.org>
> >    wrote:
> >    > I’m working around that by directly mounting the /gnustore partition
> >    > under /gnu/store now.
> > 
> >    You don't need to make a new file system and a loop mount. You could just
> >    make a bind mount.

Indeed, but I had already made the new filesystem, for other reasons.

bug#21209: /gnu/store should be able to be a symlink, but it can't

[Ludovic Courtès]

Kragen Javier Sitaker <kragen@canonical.org> skribis:

> Apparently I can’t make /gnu/store a symlink:
>
>     : user@debian:~/pkgs/guix-0.8.1; time /usr/local/bin/guix pull
>     guix pull: error: build failed: `/gnu/store' is not a directory
>
>     real	0m0.431s
>     user	0m0.104s
>     sys	0m0.036s
>     : user@debian:~/pkgs/guix-0.8.1; ls -l /gnu/store
>     lrwxrwxrwx 1 root root 9 Aug  7 12:56 /gnu/store -> /gnustore
>     : user@debian:~/pkgs/guix-0.8.1; ls -Ldl /gnu/store
>     drwxrwxr-t 40 root guix-builder 49152 Aug  7 12:56 /gnu/store
>
> Is there a reason for this?

Yes, the daemon requires the canonical file name of the store.

> It’s inconvenient.  (My root SSD only has a couple gigs left.)

Then I would suggest using a bind mount instead of a symlink.

Does that work for you?

Thanks,
Ludo’.