Compile fails using Cygwin

GROMACS version: 2021 GROMACS modification: No

Late in the build [80%] a set of errors has cropped up surrounding the declaration of 'int64_t' in file stat.cpp, on line 40

Error dump begins below, in stat.cpp:40, which references stat.h:78stat.cpp

stat.h

[ 80%] Building CXX object src/gromacs/CMakeFiles/libgromacs.dir/mdlib/trajectory_writing.cpp.o
In file included from /home/A132590/gromacs/gromacs-2021/src/gromacs/mdlib/stat.cpp:40:
/home/A132590/gromacs/gromacs-2021/src/gromacs/mdlib/stat.h:78:25: error: ‘int64_t’ was not declared in this scope
   78 | inline bool do_per_step(int64_t step, int64_t nstep)
      |                         ^~~~~~~
/home/A132590/gromacs/gromacs-2021/src/gromacs/mdlib/stat.h:78:39: error: ‘int64_t’ was not declared in this scope
   78 | inline bool do_per_step(int64_t step, int64_t nstep)
      |                                       ^~~~~~~
/home/A132590/gromacs/gromacs-2021/src/gromacs/mdlib/stat.h:78:52: error: expression list treated as compound expression in initializer [-fpermissive]
   78 | inline bool do_per_step(int64_t step, int64_t nstep)
      |                                                    ^
[ 80%] Building CXX object src/gromacs/CMakeFiles/libgromacs.dir/mdlib/update.cpp.o
make[2]: *** [src/gromacs/CMakeFiles/libgromacs.dir/build.make:7669: src/gromacs/CMakeFiles/libgromacs.dir/mdlib/stat.cpp.o] Error 1
make[2]: *** Waiting for unfinished jobs....
[ 80%] Building CXX object src/gromacs/CMakeFiles/libgromacs.dir/mdlib/update_constrain_gpu_impl.cpp.o
make[1]: *** [CMakeFiles/Makefile2:5173: src/gromacs/CMakeFiles/libgromacs.dir/all] Error 2
make: *** [Makefile:183: all] Error 2

Screenshot of make fail attached.