Error building LibreOffice on Windows (Cygwin)

Error running configure at ./autogen.sh line 322.

I couldn’t find the solution online, but I found this piece of code that I assume is generating the error:

AC_MSG_CHECKING([the dependency generation prefix (clang.exe -showIncludes)])

            echo "#include <stdlib.h>" > conftest.c

            LO_CLANG_SHOWINCLUDES_PREFIX=`$LO_CLANG_CC $CFLAGS -c -showIncludes conftest.c 2>/dev/null | \

                grep 'stdlib\.h' | head -n1 | sed 's/ [[[:alpha:]]]:.*//'`

            rm -f conftest.c conftest.obj

            if test -z "$LO_CLANG_SHOWINCLUDES_PREFIX"; then

                AC_MSG_ERROR([cannot determine the -showIncludes prefix])

            else

                AC_MSG_RESULT(["$LO_CLANG_SHOWINCLUDES_PREFIX"])

But I still don’t know what to do.