Perhaps this is just a Linux distro thing, but as someone who closely monitors the Void packages repo, dynamic linking burdens distro maintainers with hundreds of additional packages which need to be individually tracked, tested and updated.
(Packages which could otherwise be vendored by upstream and statically linked during the build.)
Dynamic linking also adds complexity to distro upgrades, because dependant packages often need to be rebuilt when the libraries they dynamically link to are changed or upgraded. For example, Void’s recent switch from LibreSSL to OpenSSL borked my install script which wasn’t aware of the change. It resulted in a built system whose XBPS package manager couldn’t verify SSL certs. On Arch, AUR packages were notoriously prone to dynamic linking errors (back when I still used it).
Personally, I don’t find the bandwidth efficiency and CVE arguments for dynamic linking to be all that convincing [1]:
Will security vulnerabilities in libraries that have been statically
linked cause large or unmanagable updates?
Findings: not really
Not including libc, the only libraries which had "critical" or "high"
severity vulnerabilities in 2019 which affected over 100 binaries on
my system were dbus, gnutls, cairo, libssh2, and curl. 265 binaries
were affected by the rest.
The total download cost to upgrade all binaries on my system which
were affected by CVEs in 2019 is 3.8 GiB. This is reduced to 1.0
GiB if you eliminate glibc.
It is also unknown if any of these vulnerabilities would have
been introduced after the last build date for a given statically
linked binary; if so that binary would not need to be updated. Many
vulnerabilities are also limited to a specific code path or use-case,
and binaries which do not invoke that code path in their dependencies
will not be affected. A process to ascertain this information in
the wake of a vulnerability could be automated.
> (Packages which could otherwise be vendored by upstream and statically linked during the build.)
The effort is approximately the same for distro maintainers. Shared libraries might mean more individual packages but the same number of projects need to be actively maintained because if a vulnerability is patched in libssl (for example) you'd need to rebuild all projects that are statically linked rather than rebuilding libssl.
Upstream vendoring doesn't really help here. If anything, it add more issues than it solves with regards to managing a distro where you want to ensure every package has the latest security patches (vendoring is more useful for teams managing specific applications to protect them against breaking changes happening upstream than it is at a distro level where you can bundle different versions of the same .so if you absolutely need to and link against those)
I.e. the few for which Linus thinks dynamic linking still can make sense ;=)
Where you can agree, you share. Where you cannot agree, you table and hold.
Perhaps we are trying to share too much.
I have removed shared libraries from internal code for similar reasons.
It is e.g. used by git, cargo (Rust's package manager) and cmake (C++ build system). It's literally installed on 99.99% of all Arch Linux systems: https://www.archlinux.de/packages/core/x86_64/curl.
There are hundreds of binaries in a Linux system and no one wants to rebuild all of them when an important library is updated.
Oh, Idunno... How certain are you of this, and why?
$ find /{,usr/}{,s}bin/ -maxdepth 1 -type f \
| wc -l
5616
$ du -h --total --no-dereference \
$(find /{,usr/}{,s}bin/ -maxdepth 1 -type f) \
| tail -n 1
1.3G total
Of course, even if we ignore the insane buld time, I don't have the source for some of those binaries, and in a few cases the source no longer exists. In those cases, should I be forced to only use those programs with the (buggy) versions of the libraries they were originally built with?
Colour me a bit surprised, and corrected.
For anyone else interested, the same solution applies to shellcheck - just install shellcheck-bin from AUR.
More importantly (for any haskell developers using Arch), there are also static builds for stack, cabal and ghcup too although you then need to maintain your own set of GHC and libraries.
I can't imagine what it must be like to use the official packages since the haskell library ecosystem is quite fast moving.
Haskell has poor support for dynamic linking. The Haskell (GHC) ABI is known to break on every compiler release. This means that every dynamically linked executable in the system needs to be recompiled. Any programs you compiled locally against dynamic system libs will break, of course.
This stance makes it much harder than necessarily for Arch users to get started with Haskell.
OMG, you really spent 95x more time, by installing of dependencies one by one? Why not just use a package manager?
The requirement that every binary on the system depend on the same shared library basically led to things like app stores and Snap, which I think we can all agree that nobody wants.
The point of software is to be composable, and vendoring kills that. Vendoring will cause free software to drown in its own complexity and is completely irresponsible.
If you have compositional packages you bake into one giant executable or something, that's still not vendoring.
Personally, I'm a big fan of just taking what you need. A little copying is better than a little dependency[1].
packages are supposed to be nodes in a dependency graph (or better, partial order), and there are nice composition rules. But one the nodes themselves represent graph/order closures (or almost-closure) we use that nice property.
People that are very application oriented tend to like vendoring --- "my application is its own island, who gives a shit". But the distro's point isn't just gather the software --- that's an anachronism --- but plan a coherent whole. And applications who only care about themselves are terrible for that.
The larger point is free and open source software really should be library-first. Siloed Applicationns are a terrible UI and holdover from the economics of proprietary shrink-wrapped software which itself is a skeuomorphism from the physical world of nonreplicable goods.
Siloed applications are UI neutral and represent decoupling, which enables progress and resilience. Excessive interdependence is how you lose Google Reader because other services have changed requirements.
> Siloed applications are UI neutral and represent decoupling, which enables progress and resilience.
The medieval manorial economy is resilient. Is that progress?
What happened to unified look and feel? and rich interactions between widgets? The smalltalk and Oberon GUI visions? All that requires more integration.
I get that we need to make the here and no work, but that is done via the en-mass translation of language-specific package manager packages to distro packages (static or shared, don't care), not vendoring.
It has been widely reported that a significant factor in that business decisions was Google’s massively coupled codebase and the fact that Reader had dependencies on parts of it that were going to have breaking changes to support other services.
> The medieval manorial economy is resilient.
It’s not, compared to capitalist and modern mixed economies, and unnecessary and counterproductive coupling between unrelated functions is a problem there, too.
> Is that progress?
Compared to its immediate precedents, generally, yes.
The future is statically linked and isolated applications. Distros need to adapt.
1. Have the users been asking for everything to be a laggy electron app? I don't think so.
2. Within these apps are languages based package managers that don't encorage vendoring, it's just one people go to package for distros that they vendor away. Distros do need to make it easier to automatically convert language-specific package manager apps.
The future is making development builds and production builds not wildly different, and both super incremental, so one can easily edit any dependency not matter how deep and then put their system back to together.
Again, I am fine with static linking. My distro, NixOS is actually great at that and I've helped work on it. But vendoring ruins everything. I hate waiting for everyone to build the same shit over and over again with no instrumentality, and I don't have time to reverse-engineer whatever special snowflake incremental dev build setup each package uses.
I'm not trying to convince you of anything, here, I'm just describing the facts on the ground. If you're not into them, that's fine!
But
- many people seem to like unified look and feel
- many people complain about per-app auto-update
- many people love to complain software is getting worse
Are these people connecting these complaints to the debate we're having? Probably not. Can these views be connected to that? Absolutely.
---
I work on distros and due edit the root dependencies, I also contribute to many libraries I use at work during work, finally, I use the same distro at work on on my own and everything is packaged the same way. So yes, it's a "unified workflow for yak shaves" and I quite like it.
I hope there can be more people like me if this stuff weren't so obnoxiously difficult.
All else equal, sure. But they'll sacrifice that in a minute if it means elimination of other toil.
> many people complain about per-app auto-update
Facts not in evidence.
> many people love to complain software is getting worse
Okay.
> I work on distros...
Well, there you go.
> 1. Have the users been asking for everything to be a laggy electron app? I don't think so.
Humongous strawman. As if electon apps are the only ones that can be statically linked?!? For shame!
But that still doesn't make my comment a strawman (because I was talking about this one specific comment), or AFAICS yours less of one: Why would you jump to "bloated Electron apps"? Sure, they may suck, but the comment you replied to was about statically linked apps; no mention of Electron at all. Unless you're saying there was, originally, and had been edited out before I saw it? If not, your reply was... OK, more charitably, at least a non sequitur.
If not, please explain how, and I'll apologise.
Personally, for instance, I'd have been perfectly happy if at least a few apps had stayed with the Android UI of a few versions back[1], before they went all flat and gesture-based. There was no demand from me, as a consumer, to imitate Apple's UI.
___ [1]: And no, that's not outmoded "skeumorphism". That concept means "imitation of physical objects", like that shell on top of Windows that was a picture of a room, with a picture of a Rolodex on top of a dedktop etc etc. In the decades since ~1985 a separate visual grammar had developed, where a gray rounded rectangle with "highlights" on the upper and left edges, "shadows" on the lower and right edges, and text in the middle meant "button" in the sense of "click here to perform an action", not any more in the original skeumorphic sense of "this is a picture of a bit of a 1980s stereo receiver".
A) "Lose", not "use", right?
B) Sounds like a lot of gobbledy-gook... Who cares about this?
C) Why should I?
> People that are very application oriented tend to like vendoring --- "my application is its own island, who gives a shit".
No, people that are very application oriented tend to like applications that work without a lot of faffing around with "dependencies" and shit they may not even know what it means.
> But the distro's point isn't just gather the software --- that's an anachronism --- but plan a coherent whole.
A) Sez who?
B) Seems to me it would be both easier and more robust to build "a coherent whole" from bits that each work on their own than from ones that depend on each other and further other ones in some (huge bunch of) complex relationship(s).
> And applications who only care about themselves are terrible for that.
As per point B) above, seems to me it's exactly the other way around.
> The larger point is free and open source software really should be library-first.
Again, sez who?
> Siloed Applicationns are a terrible UI
WTF does the UI have to do with anything?
> and holdover from the economics of proprietary shrink-wrapped software
[Citation needed]
> which itself is a skeuomorphism from the physical world of nonreplicable goods.
Shrink-wrapped diskettes or CDs are physical goods, so they can't be skeumorphic.
Then Linux distro a year out my patched censored version and link to the buggy upstream, and I have to keep telling bug reporters to not use the distro version.
To me this assertion makes no sense at all, because the whole point of a distro is to bundle together more than hundreds of packages individually tracked, tested, and updated. By default. That's the whole point of a distro, and the reason developers target specific distros. A release is just a timestamp that specifies a set of packages bundled together, and when you target a distro you're targeting those hundred of packages that are shipped together.
And you have to consider some performance penalty when using shared libraries. First you have a time penalty when loading the executable, since first you have to run the interpreter (ld-linux) and then your actual code. But also for each function call you have to make an indirect jump into it.
Only the first call has a penalty. Then you call into the PLT and the PLT contains a direct jump to the function.
Of course if it is not a hotspot, it is meaningless.
That's where maintenance branches comes in. You fix only the security issue, and push out a new version.
Although, I have mixed feeling about containers, because I fully appreciate that Unix is the application and the software that runs on it are just the calculations. In that world, sure, a shared library makes sense the same way a standard library makes sense for a programming language. Thus, a container is “just” a packaged application.
Regardless, this concept is so out of the realm of “performance” that it’s worth noting that the idea of trying to reduce memory use or hard disk space is not a valid argument for shared libraries.
CPU frequency and CPU cache are remaining small, so smaller binaries, which fit the cache, are running faster, and use less energy, and wastes less resources overall.
> Given these, it seems worthwhile to re-evaluate the tradeoffs that come with dynamic linking
Create your own distribution and show us benefits of static linking.
The solution we eventually came to was downloading the SDK on each build, using credentials baked into the downloader script:
https://github.com/ros-drivers/pointgrey_camera_driver/blob/...
The vendor was fine with this approach, and it didn't violate their TOU, though it sure did cause a bunch of pain for the maintainers of the public ROS CI infrastructure, as there were various random failures which would pop up as a consequence of this approach.
I think eventually the vendor must have relented, as the current version of the package actually does still download at build time, but at least it downloads from a local location— though if that is permissable, I don't know why the headers themselves aren't just included in the git repo.
https://www.flir.ca/products/spinnaker-sdk/
And at least one spinnaker-based driver seems to have inherited the "download the SDK from elsewhere" approach, though who knows if that's due to genuine need or just cargo-culting forward what was implemented years ago in the flycapture driver:
https://github.com/neufieldrobotics/spinnaker_sdk_camera_dri...
The "proper" approach here would of course be for Open Robotics (the ROS maintainers) to pull the debs and host them on the official ROS repos, as they do for a number of other dependencies [1], but that clearly hasn't happened [2].
I think a lot of hardware vendors who cut their teeth in the totally locked down world of industrial controls/perception still think they're protecting some fantastic trade secret or whatever by behaving like this.
[1]: https://github.com/ros-infrastructure/reprepro-updater/tree/...
- A whole lot of software is now open and freely available
- The code-changes-to-binary-updates pipeline has been greased by a couple orders of magnitude, from internet availability to CI to user expectations around automatic updates (for both commercial and non-commercial software)
- Disk space, and arguably even RAM, have become very cheap by comparison
Given these, it seems worthwhile to re-evaluate the tradeoffs that come with dynamic linking