You cannot run sage from source code, maybe you mean from a binary. I assume you have download the zip file for sagemath in ubuntu from the web of sage. Then first uninstall the sage installed with sudo apt, this is to free space as you will not use this anymore. Now go to the folder where you have unzipped the downloaded sage and copy it direction to add it to the $PATH, to do this follow these instructions. Once you have done this maybe you will need to reboot the system, and then you can call sage from any terminal just with the command sage. You cannot run sage from source code, maybe you mean from a binary. I will assume that you have download the zip tar.bz2 file for sagemath in ubuntu from the web of sage. Then first uninstall the sage installed with sudo apt, this is to free space as you will not use this anymore. Now go to the folder where you have unzipped the downloaded sage tar.bz2 file and copy it direction to add it to the$PATH, to do this follow these instructions.
Once you have done this maybe you will need to reboot the system, and then you can call sage from any terminal just with the command sage.
You cannot run sage from source code, maybe you mean from a binary. I will assume that you have download the tar.bz2 file for sagemath in ubuntu from the web of sage. Then first uninstall the sage installed with sudo apt, this is to free space as you will not use this anymore. Now go to the folder where you have unzipped the tar.bz2 file and copy it direction to add it to the \$PATH, to do this follow these instructions.
Once you have done this maybe you will need to reboot the system, and then you can call sage from any terminal just with the command sage.