can´t install gdb or gdb server

Hi All,
I am having an issue with gdb on my BeagleBone Blue. I installed the latest firmware, (bone-debian-10.3-iot-armhf-2020-04-06-4gb.img.xz), connected to the board via USB and mostly it seems to work. I want to use visual studio community C++ for cross compiling software for the board, but when trying to run something, VS complains that it could not launch gdb and suggests that I should install it. When trying to do that I get the following response:

debian@beaglebone:/var/lib/cloud9$ sudo apt-get install openssh-server g++ gdb gdbserver
Reading package lists… Done
Building dependency tree
Reading state information… Done
Package gdb is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package ‘gdb’ has no installation candidate
E: Unable to locate package gdbserver

I had assumed that gdb and gdbserver would be included in the firmware update but that seems not to be the case. Can anyone advise a solution?

Did you run? sudo apt update first to update your apt cache?