@Handoko, I'm not familiar with the problem or have informed myself extensively. Do you perhaps know if ubuntu uses wrong (FPC) dependency for lazarus somewhere and tries to (automatically) fix that (wrongly) for end-user ?
I cannot fully remember the details because those installation issues were happened long ago. I can sure to say Ubuntu is stupid.
My Lazarus was working correctly but until one day, Ubuntu Software Updater popped up to ask me to update. Version upgrades usually will take more than 1 hour to download and install, my Internet connection is not very fast. Updates only take some minutes because they only download the outdated libraries. Because that was an update so I answered 'yes' without thinking much and I didn't pay attention what items were going to be updated.
After the update, I cannot run Lazarus properly (I forget what the error message was). Luckily I have Synaptic Package Manager installed, it's really a handy tool. Synaptic Package Manager told me that the installed FPC was broken. After some inspections, I found that my FPC had been downgraded. So Ubuntu software updates can actually mean a downgrade! The weird thing is the installed Lazarus was left being unchanged.
I tried to uninstall all of the Lazarus, FPC and FPC source and reinstall them back. It failed when installing Lazarus, although I was sure I already installed the correct version of FPC and FPC source. After some testings, I found that I have to do version lockings after I install the FPC and FPC source, or Lazarus can't be installed.
Another story was, it happened when I was trying and switching between full and RC releases. I was sure I did them correctly but it just can't be installed. I gave up, I shut down my computer and had a break. When I came back, I was able to install the FPC/source/Lazarus correctly. So I believe sometimes the OS needs a reboot if I want to uninstall and install another version of the same app.
My memory is not good so if I found something important, I'll write it down. I keep the installation/uninstallation procedure in a text file. I've been using that note for years, no problem with Ubuntu-Lazarus installation so far as long as I follow the instruction.
The TS case is interesting, I wish I can sit in front of his computer to inspect the problem.
Note:
I do not use sudo dpkg to install deb packages. I use GDebi (by double clicking that deb file directly) to install. I think using GDebi is easier and it will tell you the error/status like:
- Error: A later version is already installed
- Same version is already installed
- Error: Breaks existing package ...
- Error: Conflicts with the installed package ...
- etc
Maybe the TS can try GDebi to see what the message he will get.