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rnijveld | 1 year ago

I'd like to respond to a few things. I think using dependency count as a metric is a bad idea, that metric could easily be lowered by just copying all the code over to your project. As you rightfully say, the logic has to exist one way or another. Our approach definitely wasn't that though: it was and is never our goal to have no dependencies, but we do think that dependencies should be part of the safety story, i.e. is a dependency better or worse than what you would write yourself based on your specific use case. This needle will fall much much quicker towards writing it yourself for something like sudo, but still, at least the considerations you make should stay the same, even if the decision ends up being different. Considerations such as: is the communication with the dependency team worth it for the amount of code we save, are their goals aligned with ours, is the number of transitive dependencies that I take within my codebase with this dependency small enough, how much code am I actually saving, would I even be able to do this myself, could I help the wider community with my contributing back to that dependency, etc. I do feel that right now more often than not dependencies are just bolted onto a project as needed, and no consideration is given to any burden such a dependency might have. Aside from that, I think at least a much better metric would be something like 'teams', 'groups' or 'projects' needed to keep your project working. Still not perfect, nor is any other metric, but sometimes it helps to quantify things.

Some responses to your notes:

- The trouble is that we had to re-implement an existing CLI, and as you might expect with something that evolved over a period of some 30 years, there are quite a few weird behaviors in sudo. We initially had a mostly working implementation based on clap, but could not get some parts of the CLI to parse nicely, i.e. the code just looked hacky, and had to do all kinds of post-processing to complete the parsing of the CLI, resulting in lots of additional code. Maybe we should have looked at something like lexopt, but we just went ahead and did it ourselves initially just to see how it would go, we kind of liked the result and never looked at any alternative implementations. I do believe we looked at clap alternatives for a little while to see if something would make our parsing a little easier, but lexopt didn't surface at that time for whatever reason. We're not perfect either. I do think our parsing is pretty decent though.

- We did think about contributing back, but in the end we wanted a little more control over where the password (or more precisely 'hidden input') was stored in memory, and needed some specific parts for handling TTYs (given our setuid context) resulting in us quickly deconstructing rpassword until almost nothing of it was left. I think it's a little hard to contribute those things back, but as a side project I'd love to contribute some of the changes we made back to rpassword, there just wasn't the time to do it at that time as it would be quite a bit of work.

- Glob is a hard one, as the Rust crate is not entirely compatible with how the original sudo works. But the logic has to be there one way or another and if we have to decide between libc (i.e. probably C code) and Rust, we'd prefer to go with Rust of course. That already resulted in an issue being opened for incompatibilities of course, but it's a hard one: I'd prefer to keep the Rust code, so I hope that someone who manages glob at least agrees that it should be as compatible as possible. But I can't and don't have the expectation that their team has the same priorities, and thus we are back at one of the reasons why a dependency might not always be worth it. There's always choices to be made. For now though, we'll keep the Rust crate dependency, as it works well enough!

- Thiserror is great for prototyping, but loses its value quickly once you know what kind of errors you have, it just takes a few lines of extra code. But, thinking about teams etc: given that it is not that big, and is created and maintained by dtolnay, whose code you probably already use in multiple ways in nearly any other project, it's not the worst either. For sudo-rs though, I still think it was the better choice to remove it.

- All the sudo-* packages were mostly removed because we didn't want to expose any public API for all that internal stuff. Our initial goal is to get sudo the CLI application working, not to provide all the building blocks while the API is still in flux. We initially put it all in separate crates because of compilation time worries, but in the end those worries were unfounded. It's one of those things where Rust is still somewhat limited: we can't specify these sort of semi-private dependencies in the crates ecosystem right now, if we would have been able to specify 'nobody but us can use these as a dependency' they would have probably stayed as separate crates.

BTW: I'd like to thank you for continuing to work on Clap! There might have been a time I would have been a little worried about all the breaking changes and churn happening, but since that has stabilized I couldn't be happier! I don't think there's anyone on the sudo-rs team that had anything against clap, and I did not want to single out clap in our post specifically, so I hope you don't consider it an attack against clap. At least personally I use clap in basically every other project with a CLI.

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