PolarDB-X 在编译ploardb-x DN ，make时报这样的错，怎么解决？

PolarDB-X 在编译ploardb-x DN ，make时报这样的错：

[ 67%] Building CXX object storage/innobase/CMakeFiles/innobase.dir/buf/buf0buf.cc.o
/home/mysql/polar/polardbx-engine-2.3.0/storage/innobase/buf/buf0buf.cc: In function ‘void buf_pool_create(buf_pool_t, ulint, ulint, std::mutex, dberr_t&)’:
/home/mysql/polar/polardbx-engine-2.3.0/storage/innobase/buf/buf0buf.cc:1224:44: error: ‘SYS_gettid’ was not declared in this scope
setpriority(PRIO_PROCESS, (pid_t)syscall(SYS_gettid), -20);
^~~~
/home/mysql/polar/polardbx-engine-2.3.0/storage/innobase/buf/buf0buf.cc:1224:44: note: suggested alternative: ‘my_getwd’
setpriority(PRIO_PROCESS, (pid_t)syscall(SYS_gettid), -20);
^~~~
my_getwd
make[2]: [storage/innobase/CMakeFiles/innobase.dir/buf/buf0buf.cc.o] 错误 1
make[1]: [storage/innobase/CMakeFiles/innobase.dir/all] 错误 2
make: * [all] 错误 2

版本是这个：polardbx-engine-2.3.0

按照文档中的步骤：
cmake . \
-DFORCE_INSOURCE_BUILD=ON \
-DCMAKE_BUILD_TYPE="Debug" \
-DSYSCONFDIR=~/polar/data \
-DCMAKE_INSTALL_PREFIX=/usr/local/mysql \
-DMYSQL_DATADIR=~/polar/data \
-DMYSQL_MAINTAINER_MODE=0 \
-DWITH_SSL=openssl \
-DWITH_BOOST="./extra/boost/boost_1_70_0.tar.gz"
cmake成功，make时报错，gcc/g++是 7.2.0