PREUN

/bin/sh

if [ $1 = 0 ]; then
    /usr/sbin/update-alternatives --remove go /usr/lib/golang/bin/go
fi

POSTIN

/bin/sh

/usr/sbin/update-alternatives --install /usr/bin/go \
    go /usr/lib/golang/bin/go 90 \
    --slave /usr/bin/gofmt gofmt /usr/lib/golang/bin/gofmt