On Sun, May 28, 2017 at 07:45:02AM +0530, Lakshay Garg wrote: > [Problem] Whenever a full system upgrade is run with pacman -Syyu, > pacman downloads all the packages which need to be installed and then > upgrades all at once. This approach sometimes leads to problems on > computers with unreliable internet connections as in my case. It often > happens that while downloading one of then several packages to be > upgraded, one of the download will get corrupted and in the end when > it tries to install, none of the packages would get upgraded due to a > single corrupted package. In such a case, I run pacman -Scc followed > by pacman -Syyu to try and upgrade again leading to lots of wasted > data and time. > > [Suggested Solution] What I suggest is that a new commandline flag be > created in pacman which changes the default behaviour. When the flag > is enabled, pacman downloads upgrade files for a single package (or a > few interdependent packages) and upgrade it and then move on to > upgrade other packages. Thus installing packages one-by-one. > > [Request] Please let me know if this is a possibility or is there > another way my problem can be solved without modifying pacman. I am > willing to contribute the patch myself if you can guide me on how to > proceed. Would like to know if anyone is interested.
Downloaded packages are still in your cache and won't need to be downloaded again on your next -Syu unless they're already corrupted; by blindly running -Scc you're doing exactly the thing you're trying to avoid. (The best thing you can do to save data is ceasing to unnecessarily pass -y twice every time you upgrade.) I also don't see changes in -u behavior ever being supported as it would facilitate partial updates.