Compiling nano from source, for Cygwin

Nano v.2.4.0 comes with Cygwin.
Just install Cygwin (making the appropriate selection of optional packages, of which nano is just one of many) and Hey Presto, it works.
If you want something outside the options list, it can usually (often) be rendered available by downloading the source e.g. from gnu and compiling (./configure ... make ... make install) from within Cygwin. 
Recently a patch to 2.4.0 has been made available on nano-devel which I would like to try on a Cygwin platform. I'll need to patch nano from source. So I downloaded the source.
./configure works fine.
make proceeds quite energetically for a while and then fails as follows:

gcc -DHAVE_CONFIG_H -I. -I..  -DLOCALEDIR=\"/usr/local/share/locale\" -DSYSCONFDIR=\"/usr/local/etc\" -D_XOPEN_SOURCE=600   -g -O2 -Wall -MT text.o -MD -MP -MF .deps/text.Tpo -c -o text.o text.c
text.c: In function 'do_alt_speller':
text.c:2667:5: error: unknown type name '__time_t'
     __time_t timestamp;
     ^
Makefile:411: recipe for target 'text.o' failed
make[2]: *** [text.o] Error 1
make[2]: Leaving directory '/home/user/nano-2.4.0/src'
Makefile:395: recipe for target 'all-recursive' failed
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory '/home/user/nano-2.4.0'
Makefile:333: recipe for target 'all' failed
make: *** [all] Error 2

It is possible that I have not installed enough of Cygwin (the entire provision is huge) but generally speaking I have found compilation to work all right. (I install gcc-core and any dependencies but stop there. In the past I have had to be explicit about ... bison, flex ... and some others.) 
Can anybody offer advice on what package in Cygwin Devel (or other) I might be missing that is preventing compilation of nano from source?
Or is there a tweak to the script Makefile that I need to attend to?
Thank you.
Fergus