You failed to explain how you installed it and from where.
You seem to think that /usr/bin/gambas3.gambas exists (and it doesn’t), but you did not explain why you think so. Maybe I interpret your error wrong, but that could be because you did not show the command that generated it.
I will repeat here what I mail to most new members here:
Please in the future use CODE tags around copied/pasted computer text in a post. It is the # button in the tool bar of the post editor. When applicable copy/paste complete, that is including the prompt, the command, the output and the next prompt.
To anyone using Gambas3 and experiencing the famous “gbx3: unable to find startup file” and any of the “gbr3: unable to load component” or the “Cannot load component” or “cannot find component”, here’s what works for me:
Look for the name of the component that is missing. In my case, when I run “gambas3.gambas”, it shows the following:
jasongo@localhost:~> gambas3
gbx3: unable to find startup file
jasongo@localhost:~> gambas3.gambas
ERROR: #27: Cannot load component 'gb.jit': cannot find component
**
** OOPS! INTERNAL ERROR. Program aborting, sorry! :-(
** Unable to find JIT._Abort() method
**
** ERROR: Unable to find method _Abort in class Jit. Symbol not found
**
** Please send a bug report to the gambas bugtracker [1] or to the gambas mailing-list [2].
** [1] http://gambaswiki.org/bugtracker
** [2] https://lists.gambas-basic.org/listinfo/user
**
So what I did next is to install “gambas3-gb-jit”
sudo zypper install gambas3-gb-jit
Now it loads the Gambas3 IDE perfectly. I’m using openSUSE Leap 15.4 with the Education repo.
Generally, the format of the component is gambas3-gb-NAME OF THE COMPONENT
So if the error is missing gb.image, then you just need to install gambas3-gb-image.
Another important component is gambas3-gb-dbus which is used by the tray component. In some systems this does not install as dependency so just be sure to check if this is installed in your system.
Lastly, if it does not bother you then just install every component in your development workstation. All components starts with “gambas3-gb-*” so that will cover everything said above.