install realsense2: The following packages have unmet dependencies: libgtk-3-dev

1 change sources.list :

tsinghua->aliyun
Ubuntu Replace domestic sources

2 repeat the first two process to add repository

2022-3-15 Ubuntu 16 install librealsense2

Register the server’s public key:sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-key F6E65AC044F831AC80A06380C8B3A55A6F3EFCDE || sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-key F6E65AC044F831AC80A06380C8B3A55A6F3EFCDE
In case the public key still cannot be retrieved, check and specify proxy settings: export http_proxy=“http://:”
, and rerun the command. See additional methods in the following link.

Add the server to the list of repositories:sudo add-apt-repository "deb https://librealsense.intel.com/Debian/apt-repo $(lsb_release -cs) main" -u

3 install again

problem solved!