* Add distro support for sabayon
Sabayon is a gentoo based distro with a different package manager. Does
not need any use flags or masking for the required packages.
* Add missing backslash
* Put echo string in quotes, remove extra newline
* Order gentoo/sabayon packages alphabetically.
Enable support for ubuntu-derived linux-es in installer
Checks /etc/os-release for mention of ubuntu and debian.
Linux Mint uses ID_LIKE=ubuntu, not ID_LIKE=debian (as seen in
Ubuntu 16.04, unsure about others)
* Pin avr-gcc in shell.nix pending release of 8.3.0
There's apparently a critical bug in 8.2.0, which is now the nixpkgs default. This change overrides that default in favor of the known good version. Once 8.3.0 is the default, the override can be dropped.
* Arch/Manjaro fix
