apt -s install libssl-dev
The following packages have unmet dependencies:
libssl-dev : Depends: libssl1.1 (= 1.1.1-1ubuntu2.1~18.04.9) but 1.1.1d-1+ubuntu18.04.1+deb.sury.org+2 is to be installed
E: Unable to correct problems, you have held broken packages.
apt-cache policy apt-cache libssl1.1
apt install libssl1.1=1.1.1-1ubuntu2.1~18.04.9