fix ci

.circleci/config.yml

@@ -129,6 +129,17 @@ commands:
  sudo apt remove --purge cmake
  sudo snap install cmake --classic
 
+ install-clang-10:
+ steps:
+ - run:
+ name: Install Clang 10
+ command: |
+ wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
+ echo "deb http://apt.llvm.org/focal/ llvm-toolchain-focal-10 main" | sudo tee -a /etc/apt/sources.list
+ echo "deb-src http://apt.llvm.org/focal/ llvm-toolchain-focal-10 main" | sudo tee -a /etc/apt/sources.list
+ echo "APT::Acquire::Retries \"10\";" | sudo tee -a /etc/apt/apt.conf.d/80-retries # llvm.org unreliable
+ sudo apt-get update -y && sudo apt-get install -y clang-10
+
  install-gflags:
  steps:
  - run: