Yes, there was bug in the script, in auto mode script was not downloading actual update zip package.
From your first run you can see missing downloads for UPDATE-SuperSU-v1.93.zip and UPDATE-UbuntuInstaller.zip
which is then followed by "* cannot read 'sideload' *" when script is trying to sideload non existing file.
As you correctly noticed, this has been fixed with updated script.
From your second run you cans see that both files are correctly downloaded and pushed to the device: "sending: 'sideload' 100%"
Yes, there was bug in the script, in auto mode script was not downloading actual update zip package. SuperSU- v1.93.zip and UPDATE- UbuntuInstaller .zip
From your first run you can see missing downloads for UPDATE-
which is then followed by "* cannot read 'sideload' *" when script is trying to sideload non existing file.
As you correctly noticed, this has been fixed with updated script.
From your second run you cans see that both files are correctly downloaded and pushed to the device: "sending: 'sideload' 100%"