Hi, b...@bokr.com writes:
> Hi Maxim, > > On +2022-09-16 15:00:22 -0400, Maxim Cournoyer wrote: >> Hi, >> >> Danny Milosavljevic <dan...@scratchpost.org> writes: >> >> > The latest guix system reconfigure (of yesterday) left me unable to login >> > into >> > my X session. guix system rollback DID NOT fix it. >> > >> > I would enter my password and it would "try" to login and return right >> > back to >> > the gdm login screen. >> > >> > I've since removed gdm from my OS configuration (because I have to do >> > actual >> > *work* on this computer), but I think it would have been enough to just >> > chown /var/lib/gdm and rm ~/.xsession-errors (!) in order to make it work >> > again. >> > >> > Does that mean that user ids are non-reproducible? >> > >> > Why not have user_id = hash(user_name) ? Then they *are* reproducible. >> >> That'd be cool, but how would you implement such a hash, that returns >> something fixed between 0 and 1024? That doesn't sound feasible, >> although I'm no hash function expert. >> > > To "return something fixed between 0 and 1024" (1023?) In a context > with less than 1024 users, couldn't one wrap Danny's "hash(username)" > with a local function that finds a 0..1023 index into a trusted table > of hash(username) values represented as string lines? I'm not sure I follow. If you had some pseudo-code, that might help me :-). > Similar to the idea of representing 32-bit sRGB 16-million-colors+transparency > with an 8-bit pallette index -- or even a 1-bit index for fg/bg alternates > to black/white. I'd need to read more deeply about the topic to understand, but I welcome mathematicians wizards to devise a cute little function to do that :-). > BTW, for the unlimited-number-of-users case, what sets the 1024 range limit? It's just a convention for "system" users, e.g. users typically not having a home directory, and perhaps other traits. It can differ between distributions. Some information about it here [0]. [0] https://unix.stackexchange.com/a/80279/82353 Thanks, Maxim