try something else

.github/workflows/ccpp.yml

@@ -268,8 +268,8 @@ jobs:
 
   build-and-check-gcc-5:
 
-    runs-on: ubuntu-22.04
-    container: ubuntu:18.04
+    runs-on: ubuntu-20.04
+    ##container: ubuntu:18.04
     env:
       # otherwise we hang when installing tzdata
       DEBIAN_FRONTEND: noninteractive
@@ -278,8 +278,10 @@ jobs:
 
     - name: Install Deps
       run: |
-          apt-get update;
-          apt-get install -y \
+          echo "deb http://old-releases.ubuntu.com/ubuntu zesty main" | sudo tee /etc/apt/sources.list.d/zesty.list;
+          sudo apt-add-repository -r universe;
+          sudo apt-get update;
+          sudo apt-get install -y \
                   curl \
                   automake \
                   autoconf \
@@ -291,10 +293,10 @@ jobs:
                   libmpfr-dev \
                   libmpc-dev \
                   build-essential \
-                  gcc-5 \
-                  g++-5 \
-                  gcc-5-multilib \
-                  g++-5-multilib \
+                  gcc \
+                  g++ \
+                  gcc-multilib \
+                  g++-multilib \
                   dejagnu;
           # install Rust directly using rustup
           curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --default-toolchain=1.72.0;