4.3.1 build fails in Cygwin: 'struct utmp' has no member named 'ut_tv'

Subject says it.  Build log excerpt:

gcc -c -I.
-I/home/andrex/dev/cygwin/screen/screen-4.3.1-1.x86_64/src/screen-4.3.1
-DETCSCREENRC='"/etc/screenrc"'
-DSCREENENCODINGS='"/usr/share/screen/utf8encodings"' -DHAVE_CONFIG_H
-DGIT_REV=\""`git describe --always 2>/dev/null`"\" \
     -ggdb -O2 -pipe -Wimplicit-function-declaration
-fdebug-prefix-map=/home/andrex/dev/cygwin/screen/screen-4.3.1-1.x86_64/build=/usr/src/debug/screen-4.3.1-1
-fdebug-prefix-map=/home/andrex/dev/cygwin/screen/screen-4.3.1-1.x86_64/src/screen-4.3.1=/usr/src/debug/screen-4.3.1-1
-D_GNU_SOURCE
/home/andrex/dev/cygwin/screen/screen-4.3.1-1.x86_64/src/screen-4.3.1/utmp.c
/home/andrex/dev/cygwin/screen/screen-4.3.1-1.x86_64/src/screen-4.3.1/utmp.c: In
function 'makeuser':
/home/andrex/dev/cygwin/screen/screen-4.3.1-1.x86_64/src/screen-4.3.1/utmp.c:634:4:
error: 'struct utmp' has no member named 'ut_tv'
   u->ut_tv.tv_sec = now;
    ^
Makefile:82: recipe for target 'utmp.o' failed
make: *** [utmp.o] Error 1
*** ERROR: make failed


And indeed, in Cygwin struct utmp doesn't include ut_tv.  From
/usr/include/sys/utmp.h:

struct utmp
{
 short  ut_type;
 pid_t  ut_pid;
 char   ut_line[UT_LINESIZE];
 char  ut_id[UT_IDLEN];
 time_t ut_time;
 char   ut_user[UT_NAMESIZE];
 char   ut_host[UT_HOSTSIZE];
 long   ut_addr;
};

The problem comes in utmp.c, which has a couple of instances of

  (void)time(&now);
  u->ut_tv.tv_sec = now;

What's the best way to proceed here?

Thanks,
Andrew