Problem building cygwin-3_1_7-release tagged newlib.

[Kaz Kylheku (Cygwin)]

Hi,

I'm trying to build the 3.1.7 tagged newlib. It runs into this problem:

c++wrap -O2 -g -fno-rtti -fno-exceptions -fno-use-cxa-atexit -Wall 
-Wstrict-aliasing -Wwrite-strings -fno-common -pipe -fbuiltin 
-fmessage-length=0 -MMD -Wimplicit-fallthrough=5 -Werror 
-fmerge-constants -ftracer -c -o _cygwin_crt0_common.o 
../../.././winsup/cygwin/lib/_cygwin_crt0_common.cc
In file included from ../../.././winsup/cygwin/winsup.h:83,
                  from 
../../.././winsup/cygwin/lib/_cygwin_crt0_common.cc:9:
../../.././winsup/cygwin/winlean.h:104:16: error: redefinition of 
'struct _MEM_ADDRESS_REQUIREMENTS'
   104 | typedef struct _MEM_ADDRESS_REQUIREMENTS
       |                ^~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/w32api/minwindef.h:163,
                  from /usr/include/w32api/windef.h:9,
                  from /usr/include/w32api/windows.h:69,
                  from ../../.././winsup/cygwin/winlean.h:56,
                  from ../../.././winsup/cygwin/winsup.h:83,
                  from 
../../.././winsup/cygwin/lib/_cygwin_crt0_common.cc:9:
/usr/include/w32api/winnt.h:4896:18: note: previous definition of 
'struct _MEM_ADDRESS_REQUIREMENTS'
  4896 |   typedef struct _MEM_ADDRESS_REQUIREMENTS {
       |                  ^~~~~~~~~~~~~~~~~~~~~~~~~

This looks like a clash between the installed toolchain header and the 
one in the winsup tree?

Is this a known problem?

Maybe I shouldn't be using the native Cygwin compiler for rebuilding the 
Cygwin DLL; what is the right way?