Windows, x86_64, fastdebug:

* For target hotspot_variant-server_libjvm_objs_classFileParser.obj:
classFileParser.cpp
c:/cygwin64/home/windows/worker/jdkX-windows/build/src/hotspot/share/classfile/classFileParser.cpp(5750) : error C3861: 'snprintf': identifier not found
   ... (rest of output omitted)

The call to snprintf apparently got introduced with JDK-8214777. #include <stdio.h> is probably missing in classFileParser.cpp? This probably only affects the builds with --disable-precompiled-headers, which might explain why it was not caught before integration.

runtime/os.hpp has the definition like this:
  // Provide C99 compliant versions of these functions, since some versions
  // of some platforms don't.
  static int vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0);
  static int snprintf(char* buf, size_t len, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);

The rest of the code uses jio_snprintf, though.