Comment by cryptonector
2 days ago
The whole patch quilting thing is awful. Just keep the patches as commits. It won't "trick" me or anyone else, especially if you keep them in branches that denote "debian".
Please, please, stop the nonsense with the patch quilting -- it's really cumbersome, it adds unnecessary cognitive load, it raises the bar to contributions, it makes maintenance harder, and it adds _zero value_. Patch quilting is a lose-lose proposition.
Maintaining separate upstream sources and downstream patches does provide value. Maybe not to you, but it does.
For example, it's trivial from a web browser with a couple of clicks to go and find out all the downstream changes to a package. For example to see how glibc is currently customized in debian testing/unstable you can just navigate this webpage:
https://sources.debian.org/src/glibc/2.42-6/debian/patches
If everything gets merged in the same git tree it's way harder. Harder but doable with a rebase+force push workflow, which makes collaboration way harder. Just impossible with a merge workflow.
As an upstream maintainer of several project, being able to tell at a glance and with a few clicks how one of my projects is patched in a distribution is immensely useful when bug reports are opened.
In a past job it also literally saved a ton of money because we could show legal how various upstreams were customized by providing the content of a few .debian.tar.gz tarballs with a few small, detached patches that could be analyzed, instead of massive upstream trees that would take orders of magnitude more time to go through.
> For example, it's trivial from a web browser with a couple of clicks to go and find out all the downstream changes to a package.
How is this not also true for Git? Just put all the Debian commits "on top" and use an appropriate naming convention for your branches and tags.
> If everything gets merged in the same git tree it's way harder.
Yes, so don't merge, just rebase.
> Harder but doable with a rebase+force push workflow, which makes collaboration way harder.
No force pushes, just use new branch/tag names for new releases.
> Just impossible with a merge workflow.
Not impossible but dumb. Don't use merge workflows!
> As an upstream maintainer of several project, being able to tell at a glance and with a few clicks how one of my projects is patched in a distribution is immensely useful when bug reports are opened.
Git with a suitable web front-end gives you exactly that.
> In a past job it also literally saved a ton of money because we could show legal how various upstreams were customized by providing the content of a few .debian.tar.gz tarballs with a few small, detached patches that could be analyzed, instead of massive upstream trees that would take orders of magnitude more time to go through.
`git format-patch` and related can do the moral equivalent.
Moving from a patch stack maintained by quilt to git is what this article is about.
> The whole patch quilting thing is awful. Just keep the patches as commits.
I'd say that `quilt` the utility is pretty much abandoned at this point. The name `quilt` remains in the format name, but otherwise is not relevant.
Nowadays people that maintain patches do it via `gbp-pq` (the "patch queue" subcommand of the badly named `git-buildpackage` software). `gbp-pq switch` reads the patches stored in `debian/patches/`, creates an ephemeral branch on top of the HEAD, and replays them there. Any change done to this branch (new commits, removed comments, amended commits) are transformed by `gbp-pq export` into a valid set of patches that replaces `debian/patches/`.
This mechanism introduces two extra commands (one to "enter" and one to "exit" the patch-applied view) but it allows Debian to easily maintain a mergeable Git repo with floating patches on top of the upstream sources. That's impossible to do with plain Git and needs extra tools or special workflows even outside of Debian.
> That's impossible to do with plain Git and needs extra tools or special workflows even outside of Debian
Rebase.
Also rebasing has less information available to it, so it's less likely to update cleanly than merging. Don't do it!! Just consider the diff between the new head and upstream as "the diff" and describe the reasons for it.
3 replies →
What siblings say. What you want is `git rebase`, especially with the `--onto` and `--interactive` options. You might also want something like bisect-rebase.sh[0], though there are several other things like it now.
[0] https://gist.github.com/nicowilliams/ea2fa2b445c2db50d2ee650...
Rebasing would mean there's no continuous versioning of the "patches on top", which might be undesirable. Also, the history rewriting might make cooperation difficult.
Merges would avoid those problems, but are harder to do if there are lots of conflicts, as you can't fix conflicts patch by patch.
Perhaps a workflow based on merges-of-rebases or rebase-and-overwrite-merge would work, but I don't think it's fair to say "oh just rebase".
6 replies →
That’s what git-rebase is for, and it is built into standard git.
It's worth mentioning the quilting approach likely predates the advent of git by at least a decade.. I think compatibility with git has been available for a while now and I assume there was always something more pressing than migrating the base stack to git
dgit handles the whole affair with very little fuss I've found and is quite a pleasant workflow.
What is dgit?
2 replies →
What is patch quilting, for the blissfully unaware?
https://wiki.debian.org/UsingQuilt but the short form is that you keep the original sources untouched, then as part of building the package, you apply everything in a `debian/patches` directory, do the build, and then revert them. Sort of an extreme version of "clearly labelled changes" - but tedious to work with since you need to apply, change and test, then stuff the changes back into diff form (the quilt tool uses a push/pop mechanism, so this isn't entirely mad.)
Ha yes that does sound mad. If only there was a version control system specifically designed to track changes to code...
18 replies →
> 4. No-one should have to learn about Debian Source Packages, which are bizarre, and have been obsoleted by modern version control.