LibreOffice build error

Hello,

When try to run this command:
/cygdrive/c/sources/libo-core/autogen.sh \
        
--with-external-tar=/cygdrive/c/sources/lo-externalsrc \
                       --with-junit=/cygdrive/c/sources/junit-4.10.jar \
                       --with-ant-home=/cygdrive/c/sources/apache-ant-1.9.3
\
                       --enable-pch \
                       --disable-activex --disable-atl \
                       --with-visual-studio=2013 \
                       --with-jdk-home="D:\Program Files\Java"

I always got this error, indeed I installed Ant whose version is 1.9.3,
anybody can help me?

./configure: line 38970: test: jar: integer expression expected
configure: error: no, you need at least Ant >= 1.6.0
Error running configure at /cygdrive/c/sources/libo-core/autogen.sh line
209.

Best regards
Yonggang Chen