Am Mittwoch, 23. Januar 2013 schrieb Ludovic Courtès: > And what if you roll back once you’re at the empty profile?
Then nothing should happen. > It seems more intuitive for me to error out like this, because there was > really nothing but nothingness before “hello” was installed. :-) > WDYT? No, I disagree; when I have nothing, install hello and roll back, I should be back to nothing. Some other opinions would be useful on this matter. > This is expected (same behavior as nix-env.) Profile generations are > not deleted unless you explicitly do so; this is what guarantees that > one can roll back anywhere they want. > > But I wonder if this is really worth the trouble. In my experience, a > scenario like the one above rarely happens, if ever. I find the behaviour of roll back currently very confusing, and the situation looks reasonable to me: I install hello, it works, so I keep it. I install freetype, it does not work, so I drop it again. I install file, it does not work, so I drop it again. Now I expect to have only hello, but I have hello and freetype. Of course, instead of rolling back, I can also uninstall. But the same situation occurs when one replaces the package names by different versions, I suppose. I see installing packages and rolling back as steps forward and backward. Going into direction B and back, then going into direction C and back should not leave me with one step forward in direction B. Note that I did not use nix before; so I am just arguing from what would intuitively be the correct behaviour of --roll-back for me: Being in situation A, doing something to bring me into situation B and rolling back should put me into situation A again, not something that resembles situation A, but with memories of B. Again, some other opinions would be useful. Andreas
