Use ubuntu-18.04 as build OS for linux

Signed-off-by: falkTX <[email protected]>

.github/workflows/build.yml

@@ -3,7 +3,7 @@ name: build
 on: [push, pull_request]
 
 env:
-  CACHE_VERSION_LINUX: 3
+  CACHE_VERSION_LINUX: 4
   CACHE_VERSION_MACOS: 3
   CACHE_VERSION_WIN64: 3
   DEBIAN_FRONTEND: noninteractive
@@ -13,11 +13,15 @@ jobs:
   linux-x86_64:
     runs-on: ubuntu-latest
     container:
-      # FIXME ubuntu:18.04 needs CMake 3.15
-      # FIXME ubuntu:20.04 needs meson 0.58
-      image: ubuntu:22.04
+      image: ubuntu:18.04
     steps:
-      - run: apt-get update -qq && apt-get install -yqq git
+      - name: Update git
+        run: |
+          apt-get update -qq && apt-get install -yqq curl git libpcre2-8-0
+          curl -sLO https://launchpad.net/~cjwatson/+archive/ubuntu/launchpad/+files/git_2.34.1-1ubuntu1~bpo18.04.1~ppa1_amd64.deb
+          curl -sLO https://launchpad.net/~cjwatson/+archive/ubuntu/launchpad/+files/git-man_2.34.1-1ubuntu1~bpo18.04.1~ppa1_all.deb
+          dpkg -i *.deb
+          rm *.deb
       - uses: actions/checkout@v3
         with:
           submodules: recursive
@@ -129,7 +133,7 @@ jobs:
       # FIXME use debian:12
       image: ubuntu:22.04
     steps:
-      - run: apt-get update -qq && apt-get install -yqq git
+      #- run: apt-get update -qq && apt-get install -yqq git
       - uses: actions/checkout@v3
         with:
           submodules: recursive