So, first of all you can't add-apt-repository by default on Debian, so you must install
Code:
software-properties-common
Code:
sudo apt-get install software-properties-common
Once you do that, you can do the normal
Code:
sudo apt-add-repository ppa:wpilib/toolchain
After you run this successfully, you must edit the sources file. So run
Code:
sudo nano /etc/apt/sources.list.d/wpilib-ubuntu-toolchain-zesty.list
(the file name might not be 'zesty' but it should be similar)
change any of the debian names from trusty or stretch or whatever it is to wily
then you must go to
https://launchpad.net/ubuntu/xenial/...ibisl13/0.14-2 for 64 bit or
https://launchpad.net/ubuntu/xenial/...ibisl13/0.14-2 for 32 bit
Download the .deb file and then run
Code:
sudo dpkg -i libisl13_0.14-2_amd64.deb
(or i386 for 32-bit) to install the library. This library is included with supported Ubuntu versions but isn't in Debian Stretch, so we can just install them from Ubuntu repositories
After this, run
Code:
sudo apt-get update
Code:
sudo apt-get install frc-toolchain
and then it should work!