diff --git a/pkgs/build-support/singularity-tools/default.nix b/pkgs/build-support/singularity-tools/default.nix
index 2a67169628795..f85e9745d7824 100644
--- a/pkgs/build-support/singularity-tools/default.nix
+++ b/pkgs/build-support/singularity-tools/default.nix
@@ -99,7 +99,6 @@ lib.makeExtensible (final: {
             inherit memSize;
           }
           ''
-            rmdir "$out"
             mkdir workspace
             mkfs -t ext3 -b 4096 /dev/${vmTools.hd}
             mount /dev/${vmTools.hd} workspace
diff --git a/pkgs/build-support/vm/default.nix b/pkgs/build-support/vm/default.nix
index 648fea5cd0163..8e262b20b3f63 100644
--- a/pkgs/build-support/vm/default.nix
+++ b/pkgs/build-support/vm/default.nix
@@ -240,6 +240,10 @@ rec {
 
 
   vmRunCommand = qemuCommand: writeText "vm-run" ''
+    if [ -f "''${NIX_ATTRS_SH_FILE-}" ]; then
+      source "$NIX_ATTRS_SH_FILE"
+    fi
+    source $stdenv/setup
     export > saved-env
 
     PATH=${coreutils}/bin