From 69e3aa043893ca6abede95263d2da288b006e61a Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Fri, 1 Aug 2014 17:24:55 +0200
Subject: [PATCH] Write Hydra roots as regular files instead of symlinks

Note that this requires at least NixOS/Nix@1c208f2b7ef8ffb5e6d435d703dad83223a67bd6.
---
 src/lib/Hydra/Helper/Nix.pm                | 8 ++------
 src/script/hydra-s3-backup-collect-garbage | 2 +-
 src/script/hydra-update-gc-roots           | 6 +++---
 3 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/src/lib/Hydra/Helper/Nix.pm b/src/lib/Hydra/Helper/Nix.pm
index cf41087b..9705fb9d 100644
--- a/src/lib/Hydra/Helper/Nix.pm
+++ b/src/lib/Hydra/Helper/Nix.pm
@@ -78,13 +78,9 @@ sub gcRootFor {
 
 sub registerRoot {
     my ($path) = @_;
-
     my $link = gcRootFor $path;
-
-    if (!-l $link) {
-        symlink($path, $link)
-            or die "cannot create GC root `$link' to `$path'";
-    }
+    open ROOT, ">$link" or die "cannot create GC root `$link' to `$path'";
+    close ROOT;
 }
 
 
diff --git a/src/script/hydra-s3-backup-collect-garbage b/src/script/hydra-s3-backup-collect-garbage
index 9de97be8..990fa535 100755
--- a/src/script/hydra-s3-backup-collect-garbage
+++ b/src/script/hydra-s3-backup-collect-garbage
@@ -32,7 +32,7 @@ closedir DIR;
 my @actual_roots = ();
 foreach my $link (@roots) {
     next if $link eq "." || $link eq "..";
-    push @actual_roots, readlink "$gcRootsDir/$link";
+    push @actual_roots, $Nix::Config::storeDir . "/" . $link;
 }
 
 # Don't delete a nix-cache-info file, if present
diff --git a/src/script/hydra-update-gc-roots b/src/script/hydra-update-gc-roots
index 021e1f6d..baf8c4ef 100755
--- a/src/script/hydra-update-gc-roots
+++ b/src/script/hydra-update-gc-roots
@@ -130,10 +130,10 @@ foreach my $link (@roots) {
         # Don't delete roots that are less than a day old, to prevent
         # a race where hydra-eval-jobs has added a root but
         # hydra-evaluator hasn't added them to the database yet.
-	my $st = lstat("$gcRootsDir/$link");
-	if (!defined $st) {
+        my $st = lstat("$gcRootsDir/$link");
+        if (!defined $st) {
             print STDERR "skipping link $link: $!\n";
-	} elsif ($st->ctime < $now - 24 * 60 * 60) {
+        } elsif ($st->ctime < $now - 24 * 60 * 60) {
             print STDERR "removing root $path\n";
             $rootsDeleted++;
             unlink "$gcRootsDir/$link" or warn "cannot remove $gcRootsDir/$link";