LocalStore: Allow the physical and logical store directories to differ

This is primarily to subsume the functionality of the
copy-from-other-stores substituter. For example, in the NixOS
installer, we can now do (assuming we're in the target chroot, and the
Nix store of the installation CD is bind-mounted on /tmp/nix):

  $ nix-build ... --option substituters 'local?state=/tmp/nix/var&real=/tmp/nix/store'

However, unlike copy-from-other-stores, this also allows write access
to such a store. One application might be fetching substitutes for
/nix/store in a situation where the user doesn't have sufficient
privileges to create /nix, e.g.:

  $ NIX_REMOTE="local?state=/home/alice/nix/var&real=/home/alice/nix/store" nix-build ...

1 files changed, 0 insertions, 103 deletions

diff --git a/scripts/copy-from-other-stores.pl.in b/scripts/copy-from-other-stores.pl.in
deleted file mode 100755
index 9b0615fe1a10..000000000000
--- a/scripts/copy-from-other-stores.pl.in
+++ /dev/null
@@ -1,103 +0,0 @@
-#! @perl@ -w @perlFlags@
-
-use utf8;
-use strict;
-use File::Basename;
-use IO::Handle;
-
-my $binDir = $ENV{"NIX_BIN_DIR"} || "@bindir@";
-
-
-STDOUT->autoflush(1);
-binmode STDERR, ":encoding(utf8)";
-
-my @remoteStoresAll = split ':', ($ENV{"NIX_OTHER_STORES"} or "");
-
-my @remoteStores;
-foreach my $dir (@remoteStoresAll) {
-    push @remoteStores, glob($dir);
-}
-
-exit if scalar @remoteStores == 0;
-print "\n";
-
-
-$ENV{"NIX_REMOTE"} = "";
-
-
-sub findStorePath {
-    my $storePath = shift;
-    foreach my $store (@remoteStores) {
-        my $sourcePath = "$store/store/" . basename $storePath;
-        next unless -e $sourcePath || -l $sourcePath;
-        $ENV{"NIX_DB_DIR"} = "$store/var/nix/db";
-        return ($store, $sourcePath) if
-            system("$binDir/nix-store --check-validity $storePath") == 0;
-    }
-    return undef;
-}
-
-
-if ($ARGV[0] eq "--query") {
-
-    while (<STDIN>) {
-        chomp;
-        my ($cmd, @args) = split " ", $_;
-
-        if ($cmd eq "have") {
-            foreach my $storePath (@args) {
-                print "$storePath\n" if defined findStorePath($storePath);
-            }
-            print "\n";
-        }
-
-        elsif ($cmd eq "info") {
-            foreach my $storePath (@args) {
-                my ($store, $sourcePath) = findStorePath($storePath);
-                next unless defined $store;
-
-                $ENV{"NIX_DB_DIR"} = "$store/var/nix/db";
-
-                my $deriver = `$binDir/nix-store --query --deriver $storePath`;
-                die "cannot query deriver of ‘$storePath’" if $? != 0;
-                chomp $deriver;
-                $deriver = "" if $deriver eq "unknown-deriver";
-
-                my @references = split "\n",
-                    `$binDir/nix-store --query --references $storePath`;
-                die "cannot query references of ‘$storePath’" if $? != 0;
-
-                my $narSize = `$binDir/nix-store --query --size $storePath`;
-                die "cannot query size of ‘$storePath’" if $? != 0;
-                chomp $narSize;
-
-                print "$storePath\n";
-                print "$deriver\n";
-                print scalar @references, "\n";
-                print "$_\n" foreach @references;
-                print "0\n";
-                print "$narSize\n";
-            }
-
-            print "\n";
-        }
-
-        else { die "unknown command ‘$cmd’"; }
-    }
-}
-
-
-elsif ($ARGV[0] eq "--substitute") {
-    die unless scalar @ARGV == 3;
-    my $storePath = $ARGV[1];
-    my $destPath = $ARGV[2];
-    my ($store, $sourcePath) = findStorePath $storePath;
-    die unless $store;
-    print STDERR "\n*** Copying ‘$storePath’ from ‘$sourcePath’\n\n";
-    system("@coreutils@/cp", "-rpd", $sourcePath, $destPath) == 0
-        or die "cannot copy ‘$sourcePath’ to ‘$storePath’";
-    print "\n"; # no hash to verify
-}
-
-
-else { die; }