Download not starting

[la99er]

I currently try to install plasma on my Nexus 5X
When I execute the script via ./pm-flash it detects my device and I can confirm that it is the correct device.
The script stops with the line ROOTFS_VERSION=
and no files are downloaded to the cache directory. Am I doing something wrong or is this a bug? Here is the complete log:

+ CACHEDIR=cache
+ echo 'Waiting for device to be in the fastboot mode'
Waiting for device to be in the fastboot mode
+ fastboot getvar product
< waiting for any device >
product: bullhead
Finished. Total time: 0.004s
++ fastboot getvar product
++ head -1
++ awk '-F: ' '{print $2}'
+ DEVICE_NAME=bullhead
+ confirm 'Connected device is bullhead, is that correct? [y/N]'
+ read -r -p 'Connected device is bullhead, is that correct? [y/N] ' response
Connected device is bullhead, is that correct? [y/N] y
+ case $response in
+ true
+ PLATFORM=neon
+ echo 'Continuing ...'
Continuing ...
+ getopts cp: opt
+ '[' -z '' ']'
+ download bullhead neon
+ '[' 2 -eq 0 ']'
+ mkdir -p cache/
+ pushd cache/
~/local/pm-flashtool/cache ~/local/pm-flashtool
+ echo 'Downloading latest rootfs ... '
Downloading latest rootfs ... 
+ '[' neon == neon ']'
++ curl https://images.plasma-mobile.org/rootfs_stamp
+ ROOTFS_VERSION=

[la99er]

Okay I am totally stupid ... I forgot to install curl