* Maintain integrity of the substitute and successor mappings when

  deleting a path in the store.
* Allow absolute paths in Nix expressions.
* Get nix-prefetch-url to work again.
* Various other fixes.

3 files changed, 16 insertions, 100 deletions

diff --git a/scripts/Makefile.am b/scripts/Makefile.am
index 4a1be7f8f0d4..35bb926af6d0 100644
--- a/scripts/Makefile.am
+++ b/scripts/Makefile.am
@@ -1,4 +1,4 @@
-bin_SCRIPTS = nix-switch nix-collect-garbage \
+bin_SCRIPTS = nix-collect-garbage \
  nix-pull nix-push nix-prefetch-url
 
 noinst_SCRIPTS = nix-profile.sh
diff --git a/scripts/nix-prefetch-url.in b/scripts/nix-prefetch-url.in
index 332290d40ac8..0873f5a8d7cb 100644
--- a/scripts/nix-prefetch-url.in
+++ b/scripts/nix-prefetch-url.in
@@ -22,27 +22,29 @@ print "file has hash $hash\n";
 my $out2 = "@prefix@/store/nix-prefetch-url-$hash";
 rename $out, $out2;
 
-# Create a Fix expression.
-my $fixexpr = 
-    "App(IncludeFix(\"fetchurl/fetchurl.fix\"), " .
-    "[(\"url\", \"$url\"), (\"md5\", \"$hash\")])";
+# Create a Nix expression.
+my $nixexpr =
+    "(import @datadir@/nix/corepkgs/fetchurl) " .
+    "{url = $url; md5 = \"$hash\"; system = \"@host@\"}";
+
+print "expr: $nixexpr\n";
 
 # Instantiate a Nix expression.
-print STDERR "running fix...\n";
-my $pid = open2(\*READ, \*WRITE, "fix -") or die "cannot run fix";
+print STDERR "instantiating Nix expression...\n";
+my $pid = open2(\*READ, \*WRITE, "nix-instantiate -") or die "cannot run nix-instantiate";
 
-print WRITE $fixexpr;
+print WRITE $nixexpr;
 close WRITE;
 
-my $id = <READ>;
-chomp $id;
+my $drvpath = <READ>;
+chomp $drvpath;
 
 waitpid $pid, 0;
-$? == 0 or die "fix failed";
+$? == 0 or die "nix-instantiate failed";
 
 # Run Nix.
-print STDERR "running nix...\n";
-system "nix --install $id > /dev/null";
-$? == 0 or die "`nix --install' failed";
+print STDERR "realising store expression $drvpath...\n";
+system "nix-store --realise $drvpath > /dev/null";
+$? == 0 or die "realisation failed";
 
 unlink $out2;
diff --git a/scripts/nix-switch.in b/scripts/nix-switch.in
deleted file mode 100755
index 9fcb598e30a3..000000000000
--- a/scripts/nix-switch.in
+++ /dev/null
@@ -1,86 +0,0 @@
-#! /usr/bin/perl -w
-
-use strict;
-
-my $keep = 0;
-my $sourceroot = 1;
-my $name = "current";
-my $srcid;
-
-my $argnr = 0;
-while ($argnr < scalar @ARGV) {
-    my $arg = $ARGV[$argnr++];
-    if ($arg eq "--keep") { $keep = 1; }
-    elsif ($arg eq "--no-source") { $sourceroot = 0; }
-    elsif ($arg eq "--name") { $name = $ARGV[$argnr++]; }
-    elsif ($arg =~ /^\//) { $srcid = $arg; }
-    else { die "unknown argument `$arg'" };
-}
-
-my $linkdir = "@localstatedir@/nix/links";
-
-# Build the specified package, and all its dependencies.
-my $nfid = `nix --install $srcid`;
-if ($?) { die "`nix --install' failed"; }
-chomp $nfid;
-die unless $nfid =~ /^\//;
-
-my $pkgdir = `nix --query --list $nfid`;
-if ($?) { die "`nix --query --list' failed"; }
-chomp $pkgdir;
-
-# Figure out a generation number.
-opendir(DIR, $linkdir);
-my $nr = 0;
-foreach my $n (sort(readdir(DIR))) {
-    next if (!($n =~ /^\d+$/));
-    $nr = $n + 1 if ($n >= $nr);
-}
-closedir(DIR);
-
-my $link = "$linkdir/$nr";
-
-# Create a symlink from $link to $pkgdir.
-symlink($pkgdir, $link) or die "cannot create $link: $!";
-
-# Store the id of the normal form.  This is useful for garbage
-# collection and the like.
-my $idfile = "$linkdir/$nr.id";
-open ID, "> $idfile" or die "cannot create $idfile";
-print ID "$nfid\n";
-close ID;
-
-# Optionally store the source id.
-if ($sourceroot) {
-    $idfile = "$linkdir/$nr-src.id";
-    open ID, "> $idfile" or die "cannot create $idfile";
-    print ID "$srcid\n";
-    close ID;
-}
-
-my $current = "$linkdir/$name";
-
-# Read the current generation so that we can delete it (if --keep
-# wasn't specified).
-my $oldlink = readlink($current);
-
-# Make $link the current generation by pointing $linkdir/current to
-# it.  The rename() system call is supposed to be essentially atomic
-# on Unix.  That is, if we have links `current -> X' and `new_current
-# -> Y', and we rename new_current to current, a process accessing
-# current will see X or Y, but never a file-not-found or other error
-# condition.  This is sufficient to atomically switch the current link
-# tree.
-
-print "switching $current to $link\n";
-
-my $tmplink = "$linkdir/.new_$name";
-symlink($link, $tmplink) or die "cannot create $tmplink";
-rename($tmplink, $current) or die "cannot rename $tmplink";
-
-if (!$keep && defined $oldlink) {
-    print "deleting old $oldlink\n";
-    unlink($oldlink) == 1 or print "cannot delete $oldlink\n";
-    unlink("$oldlink.id") == 1 or print "cannot delete $oldlink.id\n";
-    unlink("$oldlink-src.id");
-}