diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
index 86476689..9ae1deae 100644
--- a/.github/workflows/linux.yml
+++ b/.github/workflows/linux.yml
@@ -16,13 +16,10 @@ jobs:
       matrix:
         include:
           # Linux with GCC
-          # - {os: ubuntu-18.04, llvm: '3.9', compiler: gcc}
-          # - {os: ubuntu-18.04, llvm: '4.0', compiler: gcc}
-          # - {os: ubuntu-18.04, llvm: '5.0', compiler: gcc}
-          - {os: ubuntu-18.04, llvm: '6.0', compiler: gcc}
-          - {os: ubuntu-18.04, llvm: 7, compiler: gcc}
-          - {os: ubuntu-18.04, llvm: 8, compiler: gcc}
-          - {os: ubuntu-18.04, llvm: 9, compiler: gcc}
+          - {os: ubuntu-20.04, llvm: '6.0', compiler: gcc}
+          - {os: ubuntu-20.04, llvm: 7, compiler: gcc}
+          - {os: ubuntu-20.04, llvm: 8, compiler: gcc}
+          - {os: ubuntu-20.04, llvm: 9, compiler: gcc}
           - {os: ubuntu-20.04, llvm: 10, compiler: gcc}
           - {os: ubuntu-20.04, llvm: 10, compiler: gcc, type: Debug}
           # FIXME: Edit when KLEE is rebased to latest upstream.
@@ -31,13 +28,10 @@ jobs:
           - {os: ubuntu-22.04, llvm: 13, compiler: gcc, klee: 'no-klee'}
 
           # Linux with Clang
-          # - {os: ubuntu-18.04, llvm: '3.9', compiler: clang}
-          # - {os: ubuntu-18.04, llvm: '4.0', compiler: clang}
-          # - {os: ubuntu-18.04, llvm: '5.0', compiler: clang}
-          - {os: ubuntu-18.04, llvm: '6.0', compiler: clang}
-          - {os: ubuntu-18.04, llvm: 7, compiler: clang}
-          - {os: ubuntu-18.04, llvm: 8, compiler: clang}
-          - {os: ubuntu-18.04, llvm: 9, compiler: clang}
+          - {os: ubuntu-20.04, llvm: '6.0', compiler: clang}
+          - {os: ubuntu-20.04, llvm: 7, compiler: clang}
+          - {os: ubuntu-20.04, llvm: 8, compiler: clang}
+          - {os: ubuntu-20.04, llvm: 9, compiler: clang}
           - {os: ubuntu-20.04, llvm: 10, compiler: clang}
           - {os: ubuntu-20.04, llvm: 10, compiler: clang, type: Debug}
           # FIXME: Edit when KLEE is rebased to latest upstream.
@@ -52,23 +46,11 @@ jobs:
         with:
           submodules: true
 
-      # LLVM 7.0.x built by GCC is not ABI compatible with tools built by Clang
-      # and vice-versa.  Therefore, every instance of KLEE ended being killed
-      # by SIGSEGV.  LLVM 7.1 fixes this issue but it never made its way to
-      # Bionic's official repositories.  So let's use the LLVM repos instead.
-      #
-      # https://lists.llvm.org/pipermail/llvm-dev/2018-September/126564.html
-      - name: '[Bionic + LLVM 7.1] Add repositories'
-        if: matrix.os == 'ubuntu-18.04' && matrix.llvm == 7
-        run: |
-          wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
-          sudo apt-add-repository "deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic-7 main"
-
       - name: Install dependencies
         run: |
           sudo apt update
           sudo apt install ccache cmake clang-${{matrix.llvm}} \
-                           llvm-${{matrix.llvm}}-dev libc6-dev-i386 \
+                           llvm-${{matrix.llvm}}-dev gcc-multilib \
                            libz3-dev
 
       - name: Set environment
@@ -100,6 +82,10 @@ jobs:
             CFLAGS="-shared-libasan $CFLAGS"
             CXXFLAGS="-shared-libasan $CXXFLAGS"
 
+            # Dynamic compiler-rt libraries are not in /usr/lib
+            tmp="$(clang-${{matrix.llvm}} -print-file-name=libclang_rt.asan-x86_64.so)"
+            LD_LIBRARY_PATH="$(dirname "$tmp")"
+
             # Force coloured output
             CFLAGS="-fcolor-diagnostics $CFLAGS"
             CXXFLAGS="-fcolor-diagnostics $CXXFLAGS"
@@ -119,20 +105,19 @@ jobs:
           echo "CFLAGS=$CFLAGS" >> $GITHUB_ENV
           echo "CXXFLAGS=$CXXFLAGS" >> $GITHUB_ENV
           echo "LDFLAGS=$LDFLAGS" >> $GITHUB_ENV
+          echo "LD_LIBRARY_PATH=$LD_LIBRARY_PATH" >> $GITHUB_ENV
 
           # Set up ccache
           sudo /usr/sbin/update-ccache-symlinks
           echo "/usr/lib/ccache" >> $GITHUB_PATH
 
-          # Bionic does not create symlinks to versioned clang
-          sudo ln -sfr /usr/bin/ccache /usr/lib/ccache/clang-${{matrix.llvm}}
-          sudo ln -sfr /usr/bin/ccache /usr/lib/ccache/clang++-${{matrix.llvm}}
+          # Store the environment
           echo "CCACHE_BASEDIR=$GITHUB_WORKSPACE" >> $GITHUB_ENV
           echo "CCACHE_COMPRESS=true" >> $GITHUB_ENV
           echo "CCACHE_COMPRESSLEVEL=6" >> $GITHUB_ENV
           echo "CCACHE_DIR=$GITHUB_WORKSPACE/.ccache" >> $GITHUB_ENV
           echo "CCACHE_MAXSIZE=400M" >> $GITHUB_ENV
-          echo "::set-output name=timestamp::$(date -u -Iseconds)"
+          echo "timestamp=$(date -u -Iseconds)" >> $GITHUB_OUTPUT
 
       - name: Set up ccache
         uses: actions/cache@v3
@@ -152,11 +137,9 @@ jobs:
         if: matrix.llvm < 11
         run: |
           if [[ "${{matrix.compiler}}" = "clang" ]]; then
-            # * libclang_rt.asan-x86_64.so must be loaded as the first library
-            # * other compiler_rt libraries are not in /usr/lib
+            # libclang_rt.asan-x86_64.so must be loaded as the first library
             # See https://systemd.io/TESTING_WITH_SANITIZERS for details.
             export LD_PRELOAD="$(clang-${{matrix.llvm}} -print-file-name=libclang_rt.asan-x86_64.so)"
-            export LD_LIBRARY_PATH="$(dirname $LD_PRELOAD)"
           else
             export LD_PRELOAD="$(gcc -print-file-name=libasan.so)"
           fi
diff --git a/build.sh b/build.sh
index 4590b612..f088ab9b 100755
--- a/build.sh
+++ b/build.sh
@@ -831,7 +831,7 @@ if [ $FROM -le 6 -a "$BUILD_PREDATOR" = "yes" ]; then
 	pushd predator-${LLVM_VERSION}
 
 	if [ ! -f cl_build/CMakeCache.txt ]; then
-	        CXX=clang++ ./switch-host-llvm.sh ${ABS_SRCDIR}/llvm-${LLVM_VERSION}/build/${LLVM_CMAKE_CONFIG_DIR}
+	        ./switch-host-llvm.sh ${ABS_SRCDIR}/llvm-${LLVM_VERSION}/build/${LLVM_CMAKE_CONFIG_DIR}
 	fi
 
     build || exitmsg  "Building Predator"
diff --git a/lib/symbioticpy/symbiotic/environment.py b/lib/symbioticpy/symbiotic/environment.py
index e201943e..6395d520 100644
--- a/lib/symbioticpy/symbiotic/environment.py
+++ b/lib/symbioticpy/symbiotic/environment.py
@@ -5,6 +5,8 @@
 from . utils import err, dbg
 from . utils.utils import process_grep
 
+import re
+
 def _vers_are_same(v1, v2):
     parts1 = v1.split('.')
     parts2 = v2.split('.')
@@ -17,8 +19,11 @@ def _check_clang_in_path(llvm_version):
     if versline[0] != 0 or len(versline[1]) != 1:
         return False
 
-    parts = versline[1][0].split()
-    return _vers_are_same(parts[2].decode('utf-8'), llvm_version)
+    match = re.search(r'\d+\.\d+\.\d+', versline[1][0].decode())
+    if match is None:
+        err('Could not determine the clang version')
+
+    return _vers_are_same(match[0], llvm_version)
 
 def _set_symbiotic_environ(tool, env, opts):
     env.cwd = getcwd()
diff --git a/system-build.sh b/system-build.sh
index bce94885..f3fb34d4 100755
--- a/system-build.sh
+++ b/system-build.sh
@@ -166,11 +166,6 @@ mkdir -p $PREFIX/include
 check()
 {
 	MISSING=""
-	if ! curl --version &>/dev/null; then
-		echo "Need curl to download files"
-		MISSING="curl"
-	fi
-
 	if ! which true ; then
 		echo "Need 'which' command."
 		MISSING="which"
@@ -407,9 +402,7 @@ if [ $FROM -le 6 -a "$BUILD_PREDATOR" = "yes" ]; then
 	pushd predator-${LLVM_VERSION}
 
 	if [ ! -f cl_build/CMakeCache.txt ]; then
-		which "$LLVM_BIN_DIR/clang++" # plain clang has already been tested above
-		CC="$LLVM_BIN_DIR/clang" CXX="$LLVM_BIN_DIR/clang++" \
-			./switch-host-llvm.sh "$LLVM_DIR"
+		./switch-host-llvm.sh "$LLVM_DIR"
 	fi
 
     build || exitmsg "Failed building Predator"