I work in a lot of languages (including Go), which gives me some perspective. On the extreme ends of this issue we have Maven, which specifies hard version numbers (fuzzing is possible but culturally taboo) and NPM, which only recently acquired the ability to lock version numbers and still has a strong culture of "always grab latest".
The Maven approach is unquestionably superior; code always builds every time. If you walk away from an NPM build for nine months, the chance that it will build (let alone work as before) is vanishingly small. I waste stupid amounts of time fighting with upstream dependencies rather than delivering business value.
People break library interfaces, that's just a fact of life. The only question is whether they will break your code when you explicitly decide to bump a version, or when randomly when someone (possibly not even you) makes changes to other parts of the system.
If that's your goal. There's a middle ground which includes security updates: asking the community to follow semver. Rust devs seem to do it well and my crates build well with non-exact version numbers after not visiting them for a while. Not sure why the majority of Rust devs do a good job with this and JS devs don't. I suppose it's the strictness of the contract in the first place.
With Go, I've found popular library maintainers doing a good job at BC contract compat even when there has been only one blessed version. I don't assume giving them a bit more flexibility is going to hurt anything.
No, that doesn't work. People make mistakes, and you end up not being able to build software. It might work _most_ of the time, but when things break, it's of course always at the worst possible time.
I think Cargo got it right: use semver, but also have lock files, so you can build with _exactly_ the same dependencies later.
This is nice, but should be noted does not absolutely prevent missing backward-incompatible changes; that a function has the same signature does not mean that it has backward compatible behavior.
(With a rich enough strong, static type system, used well to start with, you might hope that all meaningful behavior changes would manifest as type changes as well, but I don't think its clear that that would actually be the case even in a perfect world, and in any case, its unlikely to be the case in real use even if it would be in the ideal case.)
I've been bit by this a few times when I've come back to code 2-3 months later and forgot to include the .cargolock so I pretty much always use the lock file these days.
Eh?
NPM didn't have package-lock.json until v5, released in 2017. Before then there was the optional shrinkwrap that nobody used, so builds were totally unreproducible.
Ruby at least had Gemfile.lock from early days. Unfortunately there have been so many compatibility problems with different versions of Ruby itself that someone needed to invent rvm, rbenv, and chruby. Getting every dependency to behave in the same Ruby version was sometimes an odyssey. Still, at least builds are reproducible... as long as you're running on the same OS/CPU arch (uh oh native code!)
Ruby is actually pretty alright given the constraints, but Node/NPM is the canonical example of how NOT to do dependency management, and they're still trying to figure out here in 2018.
npm will pick the latest version of the dependencies compatible with the package.json of the packages (package-lock.json, is not published as part of the package). This means that with npm we may end up using a version of a transitive dependency which is much later than than the one that your direct dependency was tested with.
The proposal for vgo will take the minimum version compatible with the packages, and hence pick a version which is closer to the actually tested one.
Consider all tens of thousands of CVE bugs found in widely used image, video, XML, etc. libraries. Even “updated” software is often compromised via outdated libraries.
With a “min version” approach, none of those will get patched without explicit action by a developer, who won’t do that because he doesn’t even know about the bug unless he reads the thousands of messages each day on bugtrak.
If anything, history has shown that we should be focusing package management on getting security fixes to the the end user as soon as possible.
This proposal is bad for security.
One of the issues which the vgo developers point out is that the "latest" behaviour has the perverse effect that a module A may declare a dependency of version 1.1 of a module B, and may have never been even tested on that version because the package manager always picked the latest.
In some sense, the vgo approach is saying that across hierarchy of module owners, each one should keep upgrading their manifest to the latest versions of their direct dependencies, and ensure that things keep working, rather than relying on the topmost module to pull in the latest of the entire tree of dependencies. This seems to be good for the entire ecosystem.
But that’s the problem. You’re relying on N people, including the package maintainers and end developers to all take timely action in order to get a security fix to the end user.
That simply won’t happen.
What should happen is a single package maintainer fixes a vulnerability, and that fix automatically flows through the system to all places where that package is used. And insecure versions should be made unavailable or throw a critical “I won’t build” error.
Perhaps some way of marking versions as security critical might help, but the proposed approach will leave tons of vulnerable libraries in the wild.
All the current package managers for other languages have this issue to some degree. Golang should do better with knowledge of those mistakes.
Sure, but in my experience it happens at least 10x as frequently in NPM than with Go. It's really common for me to update all my Go dependencies and everything just continues to work. With NPM I have to start looking for migration documentation and change a bunch of my code.
My main fear is that when people get used to the idea that their master repo doesn't have to have a backwards compatible interface, then updating dependencies will look awfully similar to NPM where authors change interfaces based on their weekly mood.
Have you paid the upstream developers? Because you sound like you did.
It's going to be much more painful if people have to fork when a bug is introduced lest they have to wait a week or more to get a bugfix upstreamed.
Eg I might have my module that says:
"some/pkg" v1.4.1
When the code builds it will try to use 1.4.1 EVEN IF 1.4.2 EXISTS, unless it is forced to use 1.4.2 by another module you depend on. That is, say you are using module X and it says:
"some/pkg" v1.4.2
What the minimal version selection does is say "okay one module needs >=1.4.1, another needs >=1.4.2. What is the minimal version that satisfies these requirements?" And the answer to that is `1.4.2`, so even if 1.4.8 exists, 1.4.2 is used in that scenario.
I don't know how this will work long term. I think there are definitely some concerns to consider (eg many minor version bumps are for security fixes), but the scenario you are describing - the newer version causing issues - just isn't an issue as I understand it because your code won't opt to use a newer version unless you (or another module you use) explicitly tell it to.
On the other hand, whenever you edit a direct dependency's minimum version, it could upgrade any other dependency via a cascade of minimum version upgrades. (In which case, don't commit it.) This keeps your team moving, but it might make dependency upgrades harder.
For example, it's up to each repo's owners (for applications, at least) to notice when there's a security patch to one of its transitive dependencies, and generate and test a commit. Someone will need to write a tool to do this automatically.
If the test fails: now what? I guess that's when you need to look into forking.
This doesn't just result in non-reproducible builds, but it results in them at unpredictable times and, if you have servicing branches of your code, backward through time. This is not a good property if you need to know what you are building today is the same as what you built yesterday, modulo intentional changes, or even that it will build or run.
Version pinning does not. Misusing it might, but don't do that.
Version pinning of dependencies is a tool for assuring the behavior of releases, but in development you should be generally be updating to the latest stable version of dependencies and then pinning them for the next release, not keeping the old pinned versions.
Isn't technical debt usually just the situation of having many things that should be done, but aren't? In other words, the accumulation of "don't do that" cases in code.
Sure, the things that you shouldn't do are the things that lead to technical debt. What I'm saying is that "version pinning to assure consistent behavior in stable releases" is not one of those things.
What is one of those things is "leaving pins from the last release in place in development".
Version pinning in releases is a means of providing stability for downstream users. It should be encouraged.
Leaving those pins in place while developing the next version is a source of technical debt. It should be discouraged.
Technical debt is to be handled during the development cycle, not in source code and most of the issues you bring up (bloated software, version pinning) are solved in build systems and again should not be handled by source code.
Anyone working in an enterprise enviorment, especially that has clients on different systems, would instantly crumble without being able to target specfic builds.
Legacy and long term support software is everything.
>Go should reject version pinning as incompatible with the goals of Go.
This would instantly make go a 'no-go' in any enterprise enviorment.
A //public library// should have a well thought out interface that works at least for one project and preferably for several different projects.
If the interface needs to change I agree with the recommended semantics of planning what that change should look like and creating a new named interface (API) for that specification.
Since go expects everything to build against the 'latest' version of an interface, it should be obvious what's wrong if a stale cached version is in use. Thus /expanding/ an interface / API is permissible. They should be thought of as /write only/.
You're right that it is technical debt to not be on the latest version, but if I need to roll back to a previous (of my application) version due to a regression, I want to be 100% sure I get the exact same state as I did before. If my dependency management software doesn't solve this, it's not good enough.
As soon as some tool is used to provide reproducible builds, you have effective version pinning.
If your organization values avoiding technical debt accumulation over reproducable builds, they don't don't have to use version pinning and can always run 'go get' with the '-u' flag.
> once package users are using version pinning, it's easier for package maintainers to make changes that aren't backwards compatible.
I don't think ease of making backwards incompatible changes with vgo. Both before and after vgo, backwards incompatible changes must go in a new major version / new import path. The ability to pin major versions already exists.
If you are talking about open source, it is not a problem: anyone can upgrade dependencies and make a pull request. Without version pinning, the project will always be in a "broken" state.
For example, recently I tried to run Firefox 3.5 on linux and it crashed with modern versions of gobject libraries although they are supposed to be backwards-compatible. I wish Debian package manager allowed to install an old version of a library specially for this application.
Patch changes, don't care, minor changes, don't care, major changes, you're screwed [maybe].
https://www.youtube.com/watch?v=oyLBGkS5ICk (https://github.com/matthiasn/talk-transcripts/blob/master/Hi...)
Over time, though, version pinning builds up technical debt. You have software locked to old unmaintained versions of packages. If you later try to bring some package up to date, it can break the fragile lace of dependencies locked in through past version pin decisions.
Some version pinning systems let you import multiple versions of the same package into the same build to accommodate dependencies on different version. That bloats executable code and may cause problems with multiple copies of the same data.
On the other side, once package users are using version pinning, it's easier for package maintainers to make changes that aren't backwards compatible. This makes it harder for package users to upgrade to the new package and catch up. Three years after you start version pinning, it's going to be a major effort to clean up the mess.
The Go crowd tries to avoid churn. Their language and libraries don't change too much. That's a good, practical decision. Go should reject version pinning as incompatible with the goals of Go.