I am trying to install kstars from source ,but I got the following error while configuring

./configure

checking build system type... i686-pc-linux-gnu

checking host system type... i686-pc-linux-gnu

checking target system type... i686-pc-linux-gnu

checking for a BSD-compatible install... /usr/bin/install -c

checking for -p flag to install... yes

checking whether build environment is sane... yes

checking for gawk... no

checking for mawk... mawk

checking whether make sets $(MAKE)... yes

checking for kde-config... not found

configure: error: The important program kde-config was not found!

Please check whether you installed KDE correctly.

What does it mean ,I already installed kde in my computer