sapling

I find it interesting it isn't self hosted. https://github.com/facebook/sapling

https://github.com/facebook/sapling is doing good work and they are suggesting their git server for large repositories exists.

> I also never got why we need DSLs for build systems The same reason they show up anywhere: to have the correct level of abstraction, or its cousin "signal/noise ratio." Trying to debug "gcc -o build build.cc && ./build" sounds like the 8th circle of hell to me. I can show a concrete example: https://github.com/facebook/sapling/blob/0.1.20221201-095354... So, when this raises OSError or FileNotFoundError due to some botched assumption, I guess one just attaches pdb to it and now your job is to be a python expert Or, my other favorite "what is wrong with you:" https://hg.mozilla.org/mozilla-central/file/FIREFOX_NIGHTLY_... Or, so as to not just be hating on python, this junk: https://github.com/brave/brave-browser/blob/v1.48.33/package... and its https://github.com/brave/brave-core/blob/master/build/comman... friend All of those are in a

Yeah, it's interesting to think about persisting the state we would need to make the file system more sympatico with Hermit. If we were willing to have a daemon.... Meta develops this "watchman" tool that our build infrastructure uses. I think for existing file systems we could imagine a daemon that watches the directory and caches what we need. But if we could dream of new file systems, then I want one that is basically btrfs but with O(1) file-level parallel-hashes (rather than block level). Heck maybe it could even enforce a sorted order on directories for us too. The hashes would be very useful in record-and-replay scenarios, where you could know immediately whether the input files are in your content-addressible blob storage without having to hash them every time. (We have some hash support in Meta's EdenFS FUSE file system https:

Not sure if anyone has tried this yet... but the example tutorial does not work. $ sl clone https://github.com/facebook/sapling $ cd sapling $ sl @ fafe18a24 23 minutes ago ricglz remote/main │ migrate packer to new CLI framework ~ From [0] under "Cloning your first repo". I get the following: ~/sapling (main)> sl status abort: '/full/path/sapling' is not inside a repository, but this command requires a repository! (use 'cd' to go to a directory inside a repository and try again) Hopefully this does not assume we are authenticating with GH just to clone and see sl operating? [0] https://sapling-scm.com/docs/introduction/getting-started/

I hadn't looked at the eden/scm directory, but they didn't even bother to change the README to not say "Mercurial" https://github.com/facebook/sapling/tree/main/eden/scm

We're somewhat limited by what version of clap is available in our internal monorepo. We try to keep things reasonably up-to-date though, so I'm sure we'll upgrade at some point. I believe we actually only use clap for some side binaries, not for the main sl executable. We have a custom parser for that (https://github.com/facebook/sapling/tree/main/eden/scm/lib/c...), to match the preexisting hg parse behavior. Unfortunately I'm not familiar enough with clap or why we didn't go with clap in the first place to say what we would need to use clap for the main binary.

Holy hell, did they manually recreate meson? a 1700 line setup.py ... https://github.com/facebook/sapling/blob/main/eden/scm/setup... It's a pet peeve of mine folks that use python subprocess as a replacement for bash because it takes special discipline to not eat stdout and stderr, or to correctly try:finally: to show the Proc details before the raise eats the variable

Yeah, the old Eden repository redirects directly to Sapling now: https://github.com/facebookexperimental/eden

https://sapling-scm.com/ https://github.com/facebook/sapling

Facebook uses mercurial across the board, at least from what I saw a couple years back. A good chunk of the large file / large repo has been open sourced as EdenFS [1] which uses file notifications to update the status as you make changes to amortize the cost so that it’s already computed by the time you query (watchman is integrated). That being said, very few code bases grow to this size unless you are a major tech company and have a single mono repo (with a few major OSS projects as notable counter examples). [1] https://github.com/facebookexperimental/eden

Maybe at their scale it makes more sense to switch to a VCS like Eden? https://github.com/facebookexperimental/eden Eden's equivalent of 'git status' should run almost instantaneous, as checkouts are hosted by a virtual file system (FUSE) that tracks changes.

Meta having moved on from Mercurial may be a factually true comment, but it looks like they still have fondness for Mercurial's ways: https://github.com/facebookexperimental/eden

> - A build system / package manager like Nix [1] but with a better user experience / more straightforward command-line tooling. Working on it :) > - A version control system which scales to petabytes or more. Something that I could put large video files in without thinking twice about it. Something a large company could use for their monorepo—or even their data warehouse. https://github.com/facebookexperimental/eden > A note-taking tool that allows me to organize notes in a graph with links between them https://www.orgroam.com/