diff --git a/hooks/containerbuild/debian/install-build-essential b/hooks/containerbuild/debian/install-build-essential
index 766557a..0ac1731 100755
--- a/hooks/containerbuild/debian/install-build-essential
+++ b/hooks/containerbuild/debian/install-build-essential
@@ -1,6 +1,31 @@
 #!/usr/bin/env bash
 
+HAS_SYSTEMD=$(which systemctl)
+ENGINE=chroot
+if [ ! -z "${HAS_SYSTEMD}" ]; then
+  ENGINE=systemd-nspawn
+fi
+
 ${TAMARIN_ACBUILD} environment add DEBIAN_FRONTEND noninteractive
-sudo -E ${TAMARIN_ACBUILD} run -- apt-get update
-sudo -E ${TAMARIN_ACBUILD} run -- apt-get install --yes --no-install-recommends build-essential devscripts equivs
+
+if [ "${ENGINE}" == 'chroot' ]; then
+  # Ugly fix for Python installation in chrooted environment (require /dev/urandom)
+  head -c 65536 /dev/urandom > ./urandom
+  ${TAMARIN_ACBUILD} copy ./urandom /dev/urandom
+fi
+
+sudo -E /usr/bin/env bash - <<EOF
+export PATH=${PATH}
+${TAMARIN_ACBUILD} run --engine "${ENGINE}" -- apt-get update
+${TAMARIN_ACBUILD} run --engine "${ENGINE}" -- apt-get install --yes --no-install-recommends build-essential devscripts equivs
+EOF
+
+if [ "${ENGINE}" == 'chroot' ]; then
+  # Clean up Python fix (see above)
+  sudo -E /usr/bin/env bash - <<EOF
+  export PATH=${PATH}
+  ${TAMARIN_ACBUILD} run --engine "${ENGINE}" -- rm -f /dev/urandom
+EOF
+fi
+
 ${TAMARIN_ACBUILD} environment remove DEBIAN_FRONTEND
diff --git a/hooks/containerbuild/debian/install-git b/hooks/containerbuild/debian/install-git
index 890305a..7b3a828 100755
--- a/hooks/containerbuild/debian/install-git
+++ b/hooks/containerbuild/debian/install-git
@@ -1,6 +1,15 @@
 #!/usr/bin/env bash
 
+HAS_SYSTEMD=$(which systemctl)
+ENGINE=chroot
+if [ ! -z "${HAS_SYSTEMD}" ]; then
+  ENGINE=systemd-nspawn
+fi
+
 ${TAMARIN_ACBUILD} environment add DEBIAN_FRONTEND noninteractive
-sudo -E ${TAMARIN_ACBUILD} run -- apt-get update
-sudo -E ${TAMARIN_ACBUILD} run -- apt-get install --yes --no-install-recommends git-core
+sudo -E /usr/bin/env bash - <<EOF
+export PATH=${PATH}
+${TAMARIN_ACBUILD} run --engine "${ENGINE}" -- apt-get update
+${TAMARIN_ACBUILD} run --engine "${ENGINE}" -- apt-get install --yes --no-install-recommends git-core
+EOF
 ${TAMARIN_ACBUILD} environment remove DEBIAN_FRONTEND
diff --git a/lib/build.py b/lib/build.py
new file mode 100644
index 0000000..e067568
--- /dev/null
+++ b/lib/build.py
@@ -0,0 +1,3 @@
+
+if __name__ == '__main__':
+    print('Test')
diff --git a/lib/rkt.py b/lib/rkt.py
index c34e183..60d66fc 100644
--- a/lib/rkt.py
+++ b/lib/rkt.py
@@ -29,7 +29,7 @@ def find_image_by_name(name_pattern, rkt_flags = []):
     return None
 
 def export_image(image_id, dest_file, rkt_flags = []):
-    output = run([
+    run([
         "image",
         "export",
         image_id,
diff --git a/lib/tamarin.py b/lib/tamarin.py
index f38f53b..ed8c708 100644
--- a/lib/tamarin.py
+++ b/lib/tamarin.py
@@ -6,11 +6,15 @@ def run_profile_hooks(profile, step, cwd=None, env=None):
   step_hooks = profile[step]["hooks"].split(",")
   for hook_name in step_hooks:
     hook_path = os.path.join(hooks_dir, hook_name)
+    print(hook_path)
     subprocess.call(hook_path, cwd=cwd, stdin=subprocess.PIPE, env=env)
 
 def get_hooks_dir():
   return os.path.realpath(os.path.dirname(os.path.abspath(__file__)) + "/../hooks")
 
+def get_lib_dir():
+  return os.path.realpath(os.path.dirname(os.path.abspath(__file__)) + "/../lib")
+
 def load_profile(profile_name):
   profile_filename = profile_name+".conf"
   for profile_file in get_available_profiles():
diff --git a/package b/package
index f040d8d..9214d3d 100755
--- a/package
+++ b/package
@@ -86,7 +86,8 @@ if __name__ == "__main__":
 
       # Build image
       tamarin.run_acbuild(acbuild_flags+["set-name", "image_{:d}".format(pid)])
-      tamarin.run_acbuild(acbuild_flags+["set-exec", "--", "/bin/sh", "-c", "echo Hello World"])
+      tamarin.run_acbuild(acbuild_flags+["copy-to-dir", tamarin.get_hooks_dir(), '/tamarin'])
+      tamarin.run_acbuild(acbuild_flags+["copy-to-dir", tamarin.get_lib_dir(), '/tamarin'])
 
       # Execute containerbuild hooks
       cpb_hooks_env = os.environ.copy()
@@ -98,11 +99,12 @@ if __name__ == "__main__":
       shutil.copyfile(aci_file, cached_image_file)
 
     # Start container
-    rkt.run([
+    rkt.run(rkt_flags+[
         "run",
         "--insecure-options=image",
-        aci_file, "--net=host"
-    ] + rkt_flags, as_root=True)
+        aci_file, "--net=host",
+        "--exec", "/usr/bin/python3", "--", "/tamarin/lib/build.py"
+    ], as_root=True)
 
     # Cleanup