From a510081d9cf92b6c34762e711e7d41c09bbc2f3e Mon Sep 17 00:00:00 2001
From: Michael Fabian 'Xaymar' Dirks <info@xaymar.com>
Date: Wed, 29 Jul 2020 05:31:02 +0200
Subject: [PATCH] ci: Upgrade Ubuntu to 20.04 and don't use remote LLVM

Ubuntu 20.04 has officially replaced 19.10 as the latest version, and is stable enough that people can move to it. The script doesn't change much for that. However we do remove the needless extra builds here and revert to the system installed clang version, which thanks to other pull requests now works fine. For Ubuntu 18.04 that is clang-8, while for Ubuntu 20.04 it is clang-9.
---
 .github/workflows/main.yml | 46 +++++++++++++-------------------------
 1 file changed, 16 insertions(+), 30 deletions(-)

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 35f88a5d..b28565ae 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -70,49 +70,39 @@ jobs:
     name: "Ubuntu 64-bit"
     strategy:
       matrix:
-        ubuntu: [ bionic ]
+        ubuntu: [ bionic, focal ]
         compiler: [ gcc, clang ]
-        compiler-version: [ 8, 9, 10 ]
-        exclude:
-          - ubuntu: bionic
-            compiler: gcc
-            compiler-version: 10
-          - ubuntu: bionic
-            compiler: clang
-            compiler-version: 8
         include:
           - ubuntu: bionic
             compiler: gcc
-            compiler-version: 8
             compiler-cxx: g++
             runner: ubuntu-18.04
             packages: gcc-8 g++8
             extra_command: sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-8 800 --slave /usr/bin/g++ g++ /usr/bin/g++-8
-            id: ubuntu1804-gcc8
+            id: ubuntu-18.04
           - ubuntu: bionic
+            compiler: clang
+            compiler-cxx: clang
+            compiler-version: 8
+            runner: ubuntu-18.04
+            packages: clang-8
+            extra_command: ""
+            id: ubuntu-18.04-clang
+          - ubuntu: focal
             compiler: gcc
-            compiler-version: 9
             compiler-cxx: g++
-            runner: ubuntu-latest
+            runner: ubuntu-20.04
             packages: gcc-9 g++9
             extra_command: sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-9 800 --slave /usr/bin/g++ g++ /usr/bin/g++-9
-            id: ubuntu1910-gcc9
-          - ubuntu: bionic
+            id: ubuntu-20.04
+          - ubuntu: focal
             compiler: clang
+            compiler-cxx: clang
             compiler-version: 9
-            compiler-cxx: clang++
-            runner: ubuntu-18.04
+            runner: ubuntu-20.04
             packages: clang-9
             extra_command: ""
-            id: ubuntu1804-clang9
-          - ubuntu: bionic
-            compiler: clang
-            compiler-version: 10
-            compiler-cxx: clang++
-            runner: ubuntu-latest
-            packages: clang-10
-            extra_command: ""
-            id: ubuntu1910-clang10
+            id: ubuntu-20.04-clang
     runs-on: ${{ matrix.runner }}
     env:
       CMAKE_GENERATOR: "Ninja"
@@ -127,10 +117,6 @@ jobs:
     - name: "Prerequisites: Apt-Get"
       shell: bash
       run: |
-        if [ "${{ matrix.compiler }}" == "clang" ]; then
-          wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
-          sudo add-apt-repository "deb http://apt.llvm.org/${{ matrix.ubuntu }}/ llvm-toolchain-${{ matrix.ubuntu }}-${{ matrix.compiler-version }} main"
-        fi
         sudo apt-get -qq update
         sudo apt-get purge libjpeg9-dev:amd64 libjpeg8-dev:amd64 libjpeg-turbo8-dev:amd64
         sudo apt-get install \