nix-store does not obey NIX_IGNORE_SYMLINK_STORE

[rrnewton]

When /nix is a symlink into a network file system, the current installer fails. Down inside its install script, this is what happens:

+ /nix/store/clnpynyac3hx3a6z5lsy893p7b4rwnyf-nix-1.7/bin/nix-store --init
error: `/nix' is not a directory

It would be nice if nix-store would also obey the NIX_IGNORE_SYMLINK_STORE flag, and tolerate this symlink.

Or..... perhaps this is unintended, and the current behavior is just a bug. Maybe it just should have followed the symlink when checking the file type. For example:

$ file /nix
/nix: symbolic link to `/nfs/wherever'
$ file /nix/
/nix/: directory

[wmertens]

Why not mount the NFS mount directly over /nix?
Alternatively, consider proot if what you want is user installs.

On Fri, Oct 17, 2014 at 5:00 PM, Ryan Newton notifications@github.com
wrote:

When /nix is a symlink into a network file system, the current installer
fails. Down inside its install script, this is what happens:

• /nix/store/clnpynyac3hx3a6z5lsy893p7b4rwnyf-nix-1.7/bin/nix-store --init
  error: `/nix' is not a directory

It would be nice if nix-store would also obey the NIX_IGNORE_SYMLINK_STORE
flag, and tolerate this symlink.

Or..... perhaps this is unintended, and the current behavior is just a
bug. Maybe it just should have followed the symlink when checking the file
type. For example:

$ file /nix
/nix: symbolic link to `/nfs/wherever'$ file /nix/
/nix/: directory

—
Reply to this email directly or view it on GitHub
#374.

[rrnewton]

Well, much like in #324 we are not using this on personal machines or ones where we have root.

We want to use nix precisely for reproducibility across wide-flung machines with different configurations -- for us this means various supercomputers and our university shared linux systems. In the latter cases I convinced our sysadmins to symlink /nix, but it is laborious to ask them for more. proot sounds like an interesting option.

Still, it seems like this particular "bug" should be an easy fix, and would enable this symlinked mode of installation.

[edolstra]

I can't reproduce this. This works:

$ file /tmp/root/nix
/tmp/root/nix: symbolic link to `/tmp/root/nix2'

$ file /tmp/root/nix/
/tmp/root/nix/: directory

$ NIX_IGNORE_SYMLINK_STORE=1 NIX_REMOTE= NIX_STATE_DIR=/tmp/root/db NIX_STORE_DIR=/tmp/root/nix/store nix-store --init

[rrnewton]

Huh, this is surprising. If I run the "install" shell script:

$ ./nix-binary-tarball-unpack/nix-1.7-x86_64-linux/install
....
....
+ echo 'initialising Nix database...'
initialising Nix database...
+ /nix/store/clnpynyac3hx3a6z5lsy893p7b4rwnyf-nix-1.7/bin/nix-store --init
error: `/nix' is not a directory
+ echo './nix-binary-tarball-unpack/nix-1.7-x86_64-linux/install: failed to initialize the Nix database'
./nix-binary-tarball-unpack/nix-1.7-x86_64-linux/install: failed to initialize the Nix database
+ exit 1

And then I can repeat that failed command myself till my heart's content and I still see the error:

$ /nix/store/clnpynyac3hx3a6z5lsy893p7b4rwnyf-nix-1.7/bin/nix-store --init
error: `/nix' is not a directory

Then I can add in these env vars one-by-one and still get the error:

$ NIX_IGNORE_SYMLINK_STORE=1  /nix/store/clnpynyac3hx3a6z5lsy893p7b4rwnyf-nix-1.7/bin/nix-store --init
error: `/nix' is not a directory

$ NIX_IGNORE_SYMLINK_STORE=1 NIX_REMOTE= /nix/store/clnpynyac3hx3a6z5lsy893p7b4rwnyf-nix-1.7/bin/nix-store --init
error: `/nix' is not a directory

Finally, it's NIX_STATE_DIR that seems to make it work:

$ NIX_IGNORE_SYMLINK_STORE=1 NIX_REMOTE= NIX_STATE_DIR=/tmp/root/db /nix/store/clnpynyac3hx3a6z5lsy893p7b4rwnyf-nix-1.7/bin/nix-store --init

[rrnewton]

Oh, however, that only works when NIX_STATE_DIR is outside the symlinked dir. If I set it to /nix/var/nix I still get the error:

$ NIX_IGNORE_SYMLINK_STORE=1 NIX_REMOTE= NIX_STATE_DIR=/nix/var/nix /nix/store/clnpynyac3hx3a6z5lsy893p7b4rwnyf-nix-1.7/bin/nix-store --init
error: `/nix' is not a directory

$ NIX_IGNORE_SYMLINK_STORE=1 NIX_REMOTE= NIX_STATE_DIR=/nix/var/nix NIX_STORE_DIR=/nix/store /nix/store/clnpynyac3hx3a6z5lsy893p7b4rwnyf-nix-1.7/bin/nix-store --init
error: `/nix' is not a directory

[wmertens]

What throws that error? It's not https://github.com/NixOS/nix/blob/master/src/libstore/local-store.cc#L217-L219 since the message is different...

[rrnewton]

Btw, the work-around that I'm using on some machines is to create a /nix dir, install, and then move the contents of it somewhere else, then symlink it. But if it requires going through a sysadmin for those steps thats a pain. I'll probably just instead create a tarball capturing the installed state, and reproduce the rest of the install script that sets up ~/.nix-profile/.

[knedlsepp]

I have a symlink /nix to a different filesystem. This works fine if I install things in the binary cache. Building things locally however always fails because of this impurity even though i set NIX_IGNORE_SYMLINK_STORE, as described in the docs.

[rrnewton]

Ok, so does that amount o a failure to reproduce? I'll give it a try again now that a couple years have passed.

[gilligan]

@rrnewton is this still a problem / still relevant or can this issue be closed?

[stale]

I marked this as stale due to inactivity. → More info

[stale]

I closed this issue due to inactivity. → More info