I have a bike with Avid hydraulic brakes. The levers feel loose and at the end of pushing it, there is a "soft" feeling (like when V-brakes pads aren't adjusted properly).
As I understand, it's air inside the pipes. Is there something I can try to do to fix it without opening it / refilling liquid?


Question: Error: "Sub-process /usr/bin/dpkg returned an error code (1)”
Answer: As you are running in a VM you don't want ubuntu to try to re-install grub after changing any kernel related stuff, as you don't have a boot loader of your own.

Edit

/etc/kernel-img.conf


And comment out the lines:

postinst_hook = update-grub
postrm_hook   = update-grub


You'll probably need an

sudo apt-get -f install


afterwards