diff -Nru grml2usb-0.18.5/debian/changelog grml2usb-0.19.0/debian/changelog
--- grml2usb-0.18.5/debian/changelog	2021-01-22 09:32:43.000000000 +0000
+++ grml2usb-0.19.0/debian/changelog	2022-03-21 15:19:54.000000000 +0000
@@ -1,3 +1,17 @@
+grml2usb (0.19.0) unstable; urgency=medium
+
+  [ Manuel Rom ]
+  * [40221eb] Add Github action workflows for CI/CD
+
+  [ Michael Prokop ]
+  * [3f77679] Fix vulture usage and add vulture to Build-Depends
+  * [a6cce22] Github action: do not install virtualenv +
+    python3-setuptools. Thanks to Chris Hofstaedtler
+  * [78ae858] grml2iso: support parallel execution
+  * [8126bbf] grml2iso: execute under pipefail
+
+ -- Michael Prokop <mika@grml.org>  Mon, 21 Mar 2022 16:19:54 +0100
+
 grml2usb (0.18.5) unstable; urgency=medium
 
   * [01ed11d] Fix --grub and --syslinux handling. Thanks to Ralf Moll for
diff -Nru grml2usb-0.18.5/debian/control grml2usb-0.19.0/debian/control
--- grml2usb-0.18.5/debian/control	2020-11-27 16:55:53.000000000 +0000
+++ grml2usb-0.19.0/debian/control	2021-04-24 20:48:13.000000000 +0000
@@ -14,6 +14,7 @@
  docbook-xsl,
  flake8,
  isort,
+ vulture,
  xsltproc,
 Standards-Version: 4.5.1
 Homepage: https://grml.org/grml2usb/
diff -Nru grml2usb-0.18.5/.github/workflows/check-full.yml grml2usb-0.19.0/.github/workflows/check-full.yml
--- grml2usb-0.18.5/.github/workflows/check-full.yml	1970-01-01 00:00:00.000000000 +0000
+++ grml2usb-0.19.0/.github/workflows/check-full.yml	2021-04-24 20:48:13.000000000 +0000
@@ -0,0 +1,39 @@
+name: Code Testing
+
+on:
+  push:
+  pull_request:
+  schedule:
+    - cron: '42 1 * * *'
+
+jobs:
+  codecheck:
+    runs-on: ubuntu-latest
+    name: Run codecheck
+
+    steps:
+      - name: Checkout source
+        uses: actions/checkout@v2
+
+      - name: pip install wheel (to make install black work)
+        run: pip3 install wheel
+
+      - name: pip install flake8, isort + black, vulture
+        run: pip3 install flake8 isort black vulture
+
+      - name: Codecheck execution
+        run: make codecheck
+
+  unittests:
+    runs-on: ubuntu-latest
+    name: Run unit tests
+
+    steps:
+      - name: Checkout source
+        uses: actions/checkout@v2
+
+      - name: Install pytest
+        run: pip3 install pytest
+
+      - name: Run Pytest
+        run: pytest
diff -Nru grml2usb-0.18.5/grml2iso grml2usb-0.19.0/grml2iso
--- grml2usb-0.18.5/grml2iso	2020-07-18 19:34:53.000000000 +0000
+++ grml2usb-0.19.0/grml2iso	2022-03-11 17:57:29.000000000 +0000
@@ -6,15 +6,15 @@
 # License:       This file is licensed under the GPL v2 or any later version.
 ################################################################################
 
+set -e -o pipefail
+
 # make sure we have the sbin directories in our PATH to find grml2usb ootb
 PATH="${PATH}:/sbin:/usr/local/sbin:/usr/sbin"
 
 # adjust variables if necessary through environment {{{
 # path to the grml2usb script you'd like to use
-  [ -n "$GRML2USB" ] || GRML2USB='grml2usb'
-# work directory for creating the filesystem
-  [ -n "$TMPDIR" ]   && WRKDIR="${TMPDIR}/grml2iso.tmp"
-  [ -n "$WRKDIR" ]   || WRKDIR='/tmp/grml2iso.tmp'
+[ -n "$GRML2USB" ] || GRML2USB='grml2usb'
+
 # support mkisofs as well as genisoimage
 if which xorriso >/dev/null 2>&1 ; then
   MKISOFS='xorriso -as mkisofs'
@@ -34,8 +34,6 @@
 # }}}
 
 # helper stuff {{{
-  set -e
-
   usage() {
     echo >&2 "Usage: $0 [OPTIONS] -o target.iso source1.iso [source2.iso ...]"
     echo >&2 "
@@ -54,10 +52,11 @@
                          restrictions in the bootprocess only IPs are allowed.
                          Supported protocols are: http and ftp
      -t Directory        Directory that should be used for temporary files
-                         during build. Defaults to /tmp/grml2iso.tmp if unset.
+                         during build, instead of using a temporary directory
+                         created by mktemp(1).
 
      Examples:
-     $0 -s http://192.168.23.42:8000/grml/ -o small.iso grml64-small_2018.12.iso 
+     $0 -s http://192.168.23.42:8000/grml/ -o small.iso grml64-small_2021.07.iso
 
      Will generate a file small.iso which tries to download the squashfs file from
      http://192.168.23.42:8000/grml/ - the squashfs file is placed in the same
@@ -95,10 +94,6 @@
     GRML2USB_OPTS+=(--bootoptions="fetch=$URI")
   fi
 
-  if [ -n "$WRKDIR" ] ; then
-    GRML2USB_OPTS+=(--tmpdir="$WRKDIR")
-  fi
-
 # make sure -o is specified
   [ -n "$ISOFILE" ] || usage 1
 
@@ -143,8 +138,16 @@
   esac
 # }}}
 
-# create necessary stuff under WRKDIR {{{
-  [ -d "$WRKDIR" ] && WRKDIR_EXISTED='true' || WRKDIR_EXISTED='false'
+# ensure to properly set up working directory {{{
+  WRKDIR_EXISTED='false'
+  if [ -z "$WRKDIR" ] ; then
+    WRKDIR="$(mktemp -d)"
+  else
+    [ -d "$WRKDIR" ] && WRKDIR_EXISTED='true'
+  fi
+
+  GRML2USB_OPTS+=(--tmpdir="$WRKDIR")
+
   rm -rf "$WRKDIR/cddir" "$WRKDIR/grub_tmp"
   mkdir -p "$WRKDIR/cddir"
 # }}}}
diff -Nru grml2usb-0.18.5/Makefile grml2usb-0.19.0/Makefile
--- grml2usb-0.18.5/Makefile	2020-07-18 19:34:53.000000000 +0000
+++ grml2usb-0.19.0/Makefile	2021-04-24 20:48:13.000000000 +0000
@@ -42,6 +42,10 @@
 	flake8 grml2usb
 	isort --check-only grml2usb
 	black --check grml2usb
+	vulture grml2usb test/grml2usb_test.py
+
+test:
+	pytest
 
 # graph:
 #	sudo pycallgraph grml2usb /grml/isos/grml-small_2008.11.iso /dev/sdb1