+pip freeze 2>/dev/null | egrep ^PyYAML= \
+ || pip install PyYAML >/dev/null \
+ || fatal "pip install PyYAML failed"
+
+# Preinstall forked version of libcloud, because nodemanager "pip install"
+# won't pick it up by default.
+pip freeze 2>/dev/null | egrep ^apache-libcloud==0.18.1.dev1 \
+ || pip install --pre --ignore-installed https://github.com/curoverse/libcloud/archive/apache-libcloud-0.18.1.dev1.zip >/dev/null \
+ || fatal "pip install apache-libcloud failed"