Windows build failing

[dopplershift]

Seeing this failure now on windows (through Conda), both here on AppVeyor and on conda-forge's Azure builds:

%SRC_DIR%\build\config.h(8): warning C4005: 'YY_NO_UNISTD_H': macro redefinition
660%SRC_DIR%\build\config.h(8): note: command-line arguments:  see previous definition of 'YY_NO_UNISTD_H'
661%SRC_DIR%\lib\xml.c(2161): error C2065: 'PATH_MAX': undeclared identifier
662%SRC_DIR%\lib\xml.c(2161): error C2057: expected constant expression
663%SRC_DIR%\lib\xml.c(2161): error C2466: cannot allocate an array of constant size 0
664%SRC_DIR%\lib\xml.c(2161): error C2133: 'result': unknown size
665%SRC_DIR%\lib\xml.c(2172): warning C4034: sizeof returns 0
666%SRC_DIR%\lib\xml.c(2174): warning C4034: sizeof returns 0
667%SRC_DIR%\lib\xml.c(2164): warning C4267: 'initializing': conversion from 'size_t' to 'int', possible loss of data
668NMAKE : fatal error U1077: 'C:\PROGRA~2\MI0E91~1.0\VC\bin\amd64\cl.exe' : return code '0x2'
669Stop.
670NMAKE : fatal error U1077: '"C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\BIN\amd64\nmake.exe"' : return code '0x2'
671

[semmerson]

Gosh, I hate Windows.

AppVeyor has been reporting failure for the UDUNITS-2 package for a while now. Guess I'll have to investigate. :-(