There are a few warnings as errors occurring when building on Linux with clang (clang15). Mostly these ware some kind of "unused" warnings.
Examples :

src/jdk.hotspot.agent/linux/native/libsaproc/LinuxDebuggerLocal.cpp:423:7: error: unused variable 'i' [-Werror,-Wunused-variable]
  int i;

jdk/src/jdk.hotspot.agent/linux/native/libsaproc/symtab.c:359:11: error: variable 'rslt' set but not used [-Werror,-Wunused-but-set-variable]
      int rslt;

jdk/src/jdk.jpackage/share/native/common/Log.cpp:46:28: error: unused variable 'defaultLogLevel' [-Werror,-Wunused-const-variable]
    const Logger::LogLevel defaultLogLevel = Logger::LOG_TRACE;