diff --git a/build.sh b/build.sh
index 1537751..62f2494 100755
--- a/build.sh
+++ b/build.sh
@@ -5,10 +5,20 @@ if [ -z "$BUILD_DIR" ]; then
     BUILD_DIR=build
 fi
 
+# Reset env
+while read i
+do
+    unset "$i"
+done < <(printenv | cut -d '=' -f 1 | grep -vE '^(PWD|PATH|HOME|BUILD_DIR)$')
+printenv &&
+
+# Build
 CONFIG_DIR="$(dirname "$0")" &&
+flatpak-builder $3 --arch "$2" --install-deps-from=winebarrels --install-deps-only "$BUILD_DIR" "$1" &&
+(find '.flatpak-builder/build' -delete || rm -rf ".flatpak-builder/build/*" ".flatpak-builder/build/.*") &&
 if [ -z "$4" ]; then
-    exec flatpak-builder $3 --arch "$2" --rebuild-on-sdk-change "$BUILD_DIR" "$1"
+    BUILD_DIR= exec flatpak-builder $3 --arch "$2" --sandbox --rebuild-on-sdk-change "$BUILD_DIR" "$1"
 else
-    HASH="$("$CONFIG_DIR/hash_modules.py" --installed "$1" "$2" | sed -n '1p')" &&
-    exec flatpak-builder $3 --arch "$2" --rebuild-on-sdk-change --gpg-sign=winebarrels@marko10-000.de --repo "$4" -s "WB_HASH='${HASH}'" "$BUILD_DIR" "$1"
+    HASH="$("$CONFIG_DIR/hash_modules.py" --installed "$1" "$2" | sed -n '1p')" || exit 0 &&
+    BUILD_DIR= exec flatpak-builder $3 --arch "$2" --sandbox --rebuild-on-sdk-change --repo "$4" -s "WB_HASH='${HASH}'" "$BUILD_DIR" "$1"
 fi
\ No newline at end of file
diff --git a/run_versions.sh b/run_versions.sh
new file mode 100755
index 0000000..62496ea
--- /dev/null
+++ b/run_versions.sh
@@ -0,0 +1,13 @@
+#! /usr/bin/env bash
+# Args: <source> <version> <script> <args...>
+
+if [ -z "$VERSIONS_OUT" ]
+then
+	VERSIONS_OUT=".sources"
+fi
+
+mkdir -p ".sources" &&
+while read i
+do
+	"$3" "$i" "${@:4}" || exit "$?"
+done < <("$(dirname "$0")/versions.py" -Lf "$VERSIONS_OUT" "$1" "$2")
diff --git a/versions.py b/versions.py
new file mode 100755
index 0000000..ae5662a
--- /dev/null
+++ b/versions.py
@@ -0,0 +1,48 @@
+#! /usr/bin/env python3
+
+if __name__ == "__main__":
+    import argparse
+    import os
+    import yaml
+    import sys
+
+    # Parse
+    parser = argparse.ArgumentParser(description="Generate build scripts for differend versions.")
+    parser.add_argument("source", metavar="source", type=str, nargs=1, help="The source build script to modify.")
+    parser.add_argument("versions", metavar="versions", type=str, nargs="+", help="The files they contain the version information.")
+    parser.add_argument("-f", "--files", dest="files", type=str, nargs="?", default=".", help="The target directory to save the generated scripts in. Default: \".\"")
+    parser.add_argument("-l", "--list", dest="list", action="store_const", const=True, default=False, help="Output all gerenated file names.")
+    parser.add_argument("-L", "--list-full", dest="list_full", action="store_const", const=True, default=False, help="Like --list with path from --files.")
+    args = parser.parse_args()
+
+    # Load source file
+    fileData = open(args.source[0], "r").read()
+    tmpName = os.path.basename(args.source[0]) 
+    tmp = tmpName.rfind(".")
+    if tmp >= 0:
+        configStart = tmpName[:tmp]
+        configEnding = tmpName[tmp:]
+    else:
+        configStart = tmpName[0]
+        configEnding = ""
+
+    # Parse versions
+    for version_file in args.versions:
+        versions = yaml.load(open(version_file, "r").read(), Loader=yaml.SafeLoader)
+        for version, attributes in versions.items():
+            # Gen config file
+            tmp = fileData.replace("{{VERSION}}", version)
+            for attributeID, attribute in attributes.items():
+                tmp = tmp.replace("{{" + attributeID + "}}", attribute)
+
+            # Save file
+            outFileName = "%s_%s%s" % (configStart, version, configEnding)
+            outFile = os.path.join(args.files, outFileName)
+            with open(outFile, "w") as f:
+                f.write(tmp)
+
+            # Log output
+            if args.list_full:
+                print(outFile)
+            else:
+                print(outFileName)