build-webgl and build-StandaloneLinux64-il2cpp failing with 'Could not find valid clang executable at clang' Job Failed #855740169

Job #855740169 and #856161095 failed for 8c5e0998:

Invoking il2cpp with arguments: --convert-to-cpp --emit-null-checks --enable-array-bounds-check --dotnetprofile="unityaot" --compile-cpp --libil2cpp-static --platform="Linux" --architecture="x64" --configuration="Release" --outputpath="/builds/gableroux/unity3d-gitlab-ci-example/Temp/StagingArea/Data/Native/GameAssembly.so" --cachedirectory="/builds/gableroux/unity3d-gitlab-ci-example/Assets/../Library/il2cpp_cache" --baselib-directory="/opt/unity/Editor/Data/PlaybackEngines/LinuxStandaloneSupport/Variations/linux64_withgfx_nondevelopment_il2cpp" --avoid-dynamic-library-copy --profiler-report --map-file-parser="/opt/unity/Editor/Data/Tools/MapFileParser/MapFileParser" --sysroot-path=/ --tool-chain-path=/  --directory="/builds/gableroux/unity3d-gitlab-ci-example/Temp/StagingArea/Data/Managed" --generatedcppdir="/builds/gableroux/unity3d-gitlab-ci-example/Temp/StagingArea/Data/il2cppOutput" 
/opt/unity/Editor/Data/il2cpp/build/deploy/netcoreapp3.0/il2cpp exited after 24636 ms.
Exception: /opt/unity/Editor/Data/il2cpp/build/deploy/netcoreapp3.0/il2cpp did not run properly!
Failed running "/opt/unity/Editor/Data/il2cpp/build/deploy/netcoreapp3.0/il2cpp" --convert-to-cpp --emit-null-checks --enable-array-bounds-check --dotnetprofile="unityaot" --compile-cpp --libil2cpp-static --platform="Linux" --architecture="x64" --configuration="Release" --outputpath="/builds/gableroux/unity3d-gitlab-ci-example/Temp/StagingArea/Data/Native/GameAssembly.so" --cachedirectory="/builds/gableroux/unity3d-gitlab-ci-example/Assets/../Library/il2cpp_cache" --baselib-directory="/opt/unity/Editor/Data/PlaybackEngines/LinuxStandaloneSupport/Variations/linux64_withgfx_nondevelopment_il2cpp" --avoid-dynamic-library-copy --profiler-report --map-file-parser="/opt/unity/Editor/Data/Tools/MapFileParser/MapFileParser" --sysroot-path=/ --tool-chain-path=/  --directory="/builds/gableroux/unity3d-gitlab-ci-example/Temp/StagingArea/Data/Managed" --generatedcppdir="/builds/gableroux/unity3d-gitlab-ci-example/Temp/StagingArea/Data/il2cppOutput"  
stdout:
Running il2cpp.exe in server GC mode.
il2cpp.exe didn't catch exception: System.InvalidOperationException: C++ code builder is unable to build C++ code for Linux: Could not find valid clang executable at clang
   at Unity.IL2CPP.Building.CppProgramBuilder.ThrowIfCannotBuildInCurrentEnvironment() in /Users/bokken/build/output/unity/il2cpp/Unity.IL2CPP.Building/CppProgramBuilder.cs:line 460
   at Unity.IL2CPP.Building.CppProgramBuilder.Build(IBuildStatistics& statistics) in /Users/bokken/build/output/unity/il2cpp/Unity.IL2CPP.Building/CppProgramBuilder.cs:line 97
   at il2cpp.Compilation.CompilationDriver.Run(RuntimePlatform platform, BuildingOptions buildingOptions) in /Users/bokken/build/output/unity/il2cpp/il2cpp/Compilation/CompilationDriver.cs:line 64
   at il2cpp.Program.DoRun(String[] args, RuntimePlatform platform, BuildingOptions buildingOptions) in /Users/bokken/build/output/unity/il2cpp/il2cpp/Program.cs:line 86
   at il2cpp.Program.Run(String[] args, Boolean setInvariantCulture) in /Users/bokken/build/output/unity/il2cpp/il2cpp/Program.cs:line 71
   at il2cpp.Program.Main(String[] args) in /Users/bokken/build/output/unity/il2cpp/il2cpp/Program.cs:line 36

This now happens with the new unityci/editor docker images up to v0.7 (used to work with gableroux/unity3d). We'll need to figure this out.