addons:
apt:
sources:
- - sourceline: 'deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic-9 main'
+ - sourceline: 'deb https://apt.llvm.org/bionic/ llvm-toolchain-bionic-9 main'
key_url: 'https://apt.llvm.org/llvm-snapshot.gpg.key'
packages:
clang-format-9