So, you are installing from debs downloaded from SourceForge ? Which one of those three has a dependency on a maximum package ? I would be quite surprised but I guess its possible. I would guess a 'force' would work ....
Again, are you really trying to install on U21.10 ? You most certainly will have dependency problems doing so, it will be a long way from ready right now.
If I was you, I would read that Installing Lazarus on Linux page I mentioned earlier, especially the part that talks about installing from source. Installing Lazarus (and you have not told us which package has this strange dependency) from source lets (indeed, requires) you to resolve dependencies yourself.
Davo
Yes, I got the debs from sourceforge and I mentioned that I'm using Linux Mint 20.
The last package for lazarus is the one that chokes on libgtk2.0-dev. I get:
john@desktop02:~$ sudo apt install libgtk2.0-dev
[sudo] password for john:
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
libgtk2.0-dev : Depends: libglib2.0-dev (>= 2.27.3) but it is not going to be installed
Depends: libgdk-pixbuf2.0-dev (>= 2.21.0) but it is not going to be installed
Depends: libpango1.0-dev (>= 1.20) but it is not going to be installed
Depends: libatk1.0-dev (>= 1.29.2) but it is not going to be installed
Depends: libcairo2-dev (>= 1.6.4-6.1) but it is not going to be installed
Recommends: debhelper but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
Sorry I don't know how to format the above better. Either way, I tried installing glib2.0-dev and got something similar with different deps. I've done the check for broken packges and there aren't any. I tried installing build-essential and that also told me something similar. apt-get install -y after any of these does nothing. build-essential needs libc6-dev and g++. Then I tried:
john@desktop02:~$ sudo apt-get install libc6-dev
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
libc6-dev : Depends: libc6 (= 2.31-0ubuntu9.2) but 2.31-0ubuntu9.3 is to be installed
E: Unable to correct problems, you have held broken packages.
I then tried using aptitude and anything it wants to do wants to downgrade things and I won't do that. I also won't install from source. Thanks for helping but this is getting way to deep into package dependencies and I'm getting nervous.. The machine I'm trying to install on is the system I do my personal business on and the risk of proceeding any further is too high for me.