Revision history [back]

When I updated Ubuntu from 18.04 to 20.04 and tried installing ros-noetic, I got the same error and apt-get did not show any meaningful message, but using aptitude did some help,

sudo aptitude install ros-noetic-desktop-full

It provided a list of all packages with unmet dependencies in the following manner-

The following packages have unmet dependencies:
libpcre3-dev : Depends: libpcre3 (= 2:8.39-12build1) but 2:8.44-2+ubuntu18.04.1+deb.sury.org+1 is installed
libpcre2-dev : Depends: libpcre2-8-0 (= 10.34-7) but 10.36-2+ubuntu18.04.1+deb.sury.org+2 is installed

It also provided some suggestions which could resolve the issue but after accepting those it came up with the following message

No packages will be installed, upgraded, or removed.
0 packages upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B of archives. After unpacking 0 B will be used.

and the issue was still unresolved. Then, I myself downgraded those packages using the following commands,

sudo apt install --reinstall libpcre3=2:8.39-12build1

sudo apt install --reinstall libpcre2-8-0=10.34-7

After that apt install worked for me.