This avoids re-initializing the Flake object deep in the tree, which in turn leads to issue when overriding the Flake for testing, eg the URl would reset.
I ran into this error when trying to run `opendkim-genkey` in a vars
generator:
```console
=========================================================================== Command ===========================================================================
nix \
--extra-experimental-features 'nix-command flakes' \
shell \
--inputs-from /nix/store/9r3ddw80dz4qzci9pj57ppbh6gy2pgv9-clan-cli/lib/python3.12/site-packages/clan_cli/nixpkgs \
'nixpkgs#bash' \
'nixpkgs#bubblewrap' \
-c bwrap \
--unshare-all --tmpfs \
/ \
--ro-bind /nix/store \
/nix/store \
--dev /dev \
--bind /tmp/nix-shell.ClOjgJ/vars-kh4qrnas \
/tmp/nix-shell.ClOjgJ/vars-kh4qrnas \
--chdir / \
--bind /proc \
/proc \
--uid 1000 \
--gid 1000 \
-- bash \
-c /nix/store/p0089w4y1w3h535g7ipv4jl4r6mb2hs2-generator-dkim-playground.jflei.com.mail
=========================================================================== Stderr ============================================================================
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = (unset),
LC_ALL = (unset),
LC_CTYPE = (unset),
LC_NUMERIC = (unset),
LC_COLLATE = (unset),
LC_TIME = (unset),
LC_MESSAGES = (unset),
LC_MONETARY = (unset),
LC_ADDRESS = (unset),
LC_IDENTIFICATION = (unset),
LC_MEASUREMENT = (unset),
LC_PAPER = (unset),
LC_TELEPHONE = (unset),
LC_NAME = (unset),
LANG = "en_US.UTF-8"
are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
Can't exec "/bin/sh": No such file or directory at /nix/store/nfawbww80p1hgpymfgq1vq8wqlak75yh-opendkim-2.11.0-Beta2/sbin/.opendkim-genkey-wrapped line 139.
.opendkim-genkey-wrapped: openssl died with signal %d
127
Return Code: 1
1 hosts failed with an error. Check the logs above
```
As we allow `/bin/sh` in the nix build sandbox, I assume we're OK
allowing it here as well?
On macOS mktemp returns a temporary directory in a symlink.
Nix has a bug where it won't accept path:// located in a symlink.
This avoid this issue by always resolving symlinks as returned by
TemporaryDirectory.
Prior to this, when initializing new machines, only the current user had access to it's key which prevents other admin users to deploy this machine later
