Hello Maxime, Maxime Devos <maximede...@telenet.be> ezt írta (időpont: 2022. febr. 28., H, 19:51):
> Ludovic Courtès schreef op ma 28-02-2022 om 14:17 [+0100]: > > Hi, > > > > Maxime Devos <maximede...@telenet.be> skribis: > > > > > 2. Instead of building all of Guix as a single derivation, > > > create a DAG of derivations. More concretely: > > > > > > First read the *.scm files to determine which module imports > > > which modules. Then to compile, say, (gnu packages acl), > > > a derivation taking gnu/packages/acl.scm and its dependencies > > > gnu/packages/attr.go, gnu/packages/base.go, ... is made > > > compiling gnu/packages/acl.scm to a gnu/packages/acl.go. > > > > > > Then to build all of Guix, 'union-build' or 'file-union' is used. > > > > This is what (guix self), used by ‘guix pull’, is already doing. > > > > However, currently, package modules are split in just two groups: the > > “base” group is the closure of (guix packages base), and the second > > group has all the rest: > > > > [...] > > Looking at (guix self), it also has a few groups for non-package > modules (system tests, scripts, ...). > > > At its core though, the situation pretty much reflects the free software > > situation: there are low-level packages (glibc, GCC, GTK, etc.) that > > might depend on high-level packages (Python, Pandoc, Rust, etc.). > > > > It’s not easy to split this spaghetti ball in smaller groups. > > It's not easy to manually split the spaghetti, but we don't have > to, we could let the computer split the spaghetti for us (at least > partially, because of the circular imports), by computing the graph of > strongly-connected components and considering each SCC to be a ‘group’, > some of which depend on other groups, forming a DAG. > I was thinking about a bit of a different structure that can also be automated. My original idea was to use the already existing tree structure of the derivations, and split it based on depth. I think that gives a bit more structure, but might require splitting things that now are together (for example iirc sometimes we are defining bootstrap packages inheriting from the fully fledged ones, which introduces a syntactic dependency on something that is higher up the tree). Wdyt? Regards, g_bor > I believe Ricardo Wurmus has some script for computing the SCC? > > Splitting large SCC in smaller parts can be left as an exercise > for later, it's a somewhat orthogonal concern. > > > Thoughts? > > I think it would be nice to let (guix self) automatically determine the > DAG of groups. It would reduce the ad-hocness of the *...-modules* > variables (some care required for patches, guix/man-db.scm, .js ...). > > It would also make the node tree wide, which could reduce memory usage > (which might help with the ‘guix pull segfaults on i686-linux’ > reports). In case of a crash (*), "guix pull" does not have to start > over from scratch, which would also help with those reports. > > (*) This does not help with "failed to compute the derivation of Guix". > > Some work would be required, but I think it will be worth it, and it > only has to be done once. > > TBC, this was just an idea I wanted to share, I won't be working on it > in the forseeable future. > > Greetings, > Maxime. >
