diff --git a/kiss b/kiss
index 9363c48..913e50d 100755
--- a/kiss
+++ b/kiss
@@ -453,23 +453,26 @@ pkg_source_tar() {
     # This is a portable shell implementation of GNU tar's
     # '--strip-components 1'. Use of this function denotes a
     # performance penalty.
-    unset _seen
-
+    tmp_file "$repo_name" tarball
     tmp_file "$repo_name" tarball-manifest
 
-    # Decompress the tarball and extract it to the current directory.
-    # Store its verbose output in a file for use below.
-    decompress "$1" | tar xvf - > "$_tmp_file" ||
+    unset _seen
+
+    decompress "$1" > "$_tmp_file_pre" ||
+        die "$repo_name" "Failed to decompress $1"
+
+    tar xf "$_tmp_file_pre" ||
         die "$repo_name" "Failed to extract $1"
 
+    # The sort command filters out all duplicate top-level
+    # directories from the tarball's manifest. This is an optimization
+    # as we avoid looping (4000 times for Python(!)).
+    tar tf "$_tmp_file_pre" | sort -ut / -k1,1 > "$_tmp_file" ||
+        die "$repo_name" "Failed to extract manifest"
+
     # Iterate over all directories in the first level of the
     # tarball's manifest. Each directory is moved up a level.
     while IFS=/ read -r dir _; do case ${dir#.} in *?*)
-        # Skip directories we have seen before. This used to be a
-        # sort call but with pipe shenanigans and error handling,
-        # this is the better solution.
-        ! contains "$_seen" "$dir" || continue && _seen="$_seen $dir"
-
         # Move the parent directory to prevent naming conflicts
         # with the to-be-moved children.
         mv -f "$dir" "$KISS_PID-$dir"
@@ -491,6 +494,9 @@ pkg_source_tar() {
         # as we may leave files in here if any were copied.
         rm -rf "$KISS_PID-$dir"
     esac done < "$_tmp_file"
+
+    # Remove the tarball now that we are done with it.
+    rm -f "$_tmp_file_pre"
 }
 
 pkg_extract() {