From 886c92332c8c9ecf62de9ab12789a6c4ee5207fc Mon Sep 17 00:00:00 2001
From: Alex Biehl <alex.biehl@target.com>
Date: Sat, 23 May 2020 22:31:34 +0200
Subject: [PATCH] dockerTools: Properly add /nix/ and /nix/store/ first to
 layer.tar

In https://github.com/NixOS/nixpkgs/pull/58431 the authors ensured that
the resulting layer.tar would always list

  /nix/
  /nix/store/

first to fully comply to the tar spec. Various refactorings later it is only
ensured to create /nix/ but NOT /nix/store anymore. Instead tar transformed
them to /nix/nix and /nix/nix/store.
---
 pkgs/build-support/docker/store-path-to-layer.sh | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/pkgs/build-support/docker/store-path-to-layer.sh b/pkgs/build-support/docker/store-path-to-layer.sh
index d834716e4b2..7437da51cc4 100755
--- a/pkgs/build-support/docker/store-path-to-layer.sh
+++ b/pkgs/build-support/docker/store-path-to-layer.sh
@@ -30,12 +30,13 @@ mkdir -p nix/store
 # store path to the absolute store path.
 tarhash=$(
   basename -a "$@" |
-    tar -cp nix \
-      -C /nix/store --verbatim-files-from --files-from - \
+    tar --create --preserve-permissions --absolute-names nix \
+      --directory /nix/store --verbatim-files-from --files-from - \
       --hard-dereference --sort=name \
       --mtime="@$SOURCE_DATE_EPOCH" \
       --owner=0 --group=0 \
-      --transform 's,^nix(/|$),/nix/,' \
+      --transform 's,^nix$,/\0,' \
+      --transform 's,^nix/store$,/\0,' \
       --transform 's,^[^/],/nix/store/\0,rS' |
     tee "$layerPath/layer.tar" |
     tarsum