build filed with error

[Junhao-Fang]

my qt version is
QMake version 3.1
Using Qt version 5.15.2 in /home/eric/anaconda3/lib

but
when i make ,it says
/usr/bin/ld: ./libgecodeflatzinc.so: undefined reference to qt_version_tag@Qt_5.15' /usr/bin/ld: ./libgecodegist.so: undefined reference to QLinearGradient::~QLinearGradient()@Qt_5'

what can i do to solve it