[www-scripts] Sphinx Doc Update: ERROR

[www-data via www-scripts]

/opt/tools/sphinx_update.sh: warning: removing stale lock file from PID 19040.
UPDATING clang-tools-extra SOURCES
Updating '.':
A    test/clang-tidy/bugprone-argument-comment-literals.cpp
U    clangd/IncludeFixer.cpp
U    docs/clang-tidy/checks/bugprone-argument-comment.rst
U    docs/ReleaseNotes.rst
U    clang-tidy/bugprone/ArgumentCommentCheck.cpp
U    clang-tidy/bugprone/ArgumentCommentCheck.h
U    clang-tidy/readability/ConstReturnTypeCheck.cpp
U    unittests/clangd/DiagnosticsTests.cpp
Updated to revision 353535.
-- Could NOT find Z3 (missing:  Z3_LIBRARIES Z3_INCLUDE_DIR) (Required is at least version "4.7.1")
CMake Error at cmake/modules/CheckCompilerVersion.cmake:40 (message):
  Host GCC version should be at least 5.1 because LLVM will soon use new C++
  features which your toolchain version doesn't support.  Your version is
  4.8.4.  You can temporarily opt out using
  LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN, but very soon your toolchain won't be
  supported.
Call Stack (most recent call first):
  cmake/modules/CheckCompilerVersion.cmake:45 (check_compiler_version)
  cmake/config-ix.cmake:13 (include)
  CMakeLists.txt:655 (include)


-- Configuring incomplete, errors occurred!
See also "/opt/sphinx-docs/build/llvm/CMakeFiles/CMakeOutput.log".
See also "/opt/sphinx-docs/build/llvm/CMakeFiles/CMakeError.log".
make[1]: *** [cmake_check_build_system] Error 1
make: *** [tools/clang/tools/extra/docs/CMakeFiles/docs-clang-tools-html.dir/rule] Error 2