4 ms·

Git never forgets, this isn't really a shocking revelation.

by SillyUsername 1y ago

eviks 1y ago
What specific property of git mandates a website to not clean up those dangling commits?
- orthoxerox 1y ago
  Git has no de jure hierarchy of repositories. We de facto treat the GH repo as the primary one (and call it "origin"), but mechanically it's a peer repo. Even though it lets other repos push it around a bit and obeys commands like "change the branch to point to another commit", there are no commands to force it to delete the data.
  - eviks 1y ago
    > Even though it lets other repos push it around So there is hierarchy > there are no commands to force it to delete the data. That's just the current state, the question was how git prevents "de facto" deletion on a server? How is it anti-git to ask the server to execute git garbage collection commands, for example?
tux3 1y ago
Git does forget, it has a gc mechanism specifically for forgetting. GitHub can't use the native git gc, and apparently doesn't have their own fork-aware and weird-cross-repo-merge-aware gc, so they might just not have built a way to track which commits are dangling. But that's not obvious at all.
- lelandfe 1y ago
  How to make git an elephant: https://donatstudios.com/yagni-git-gc https://donatstudios.com/yagni-git-gc
- SillyUsername 1y ago
  Ah right, so forking the codebase, then deleting the original repo forces git to forget all copies. Gotcha thanks for the enlightenment.
tossandthrow 1y ago
Git is not point in time backups. It is versioning. You are free to organize your version history as you fit, and you can certainly rewrite history. The only issue you might have is signed commits from collaborators, that you can not resign.
- lloeki 1y ago
  > and you can certainly rewrite history. But you can't coerce everyone in the world to remove all traces of the alternate history that was a thing before being rewritten. So while you can make git forget something in your local repo, you can't make git forget across the decentralised set of repos, which is part of git's core design. So in that sense, yes, git never forgets, by design.
- deleted 1y ago
  [deleted]

Git never forgets, this isn't really a shocking revelation.

eviks 1y ago

What specific property of git mandates a website to not clean up those dangling commits?

orthoxerox 1y ago
Git has no de jure hierarchy of repositories. We de facto treat the GH repo as the primary one (and call it "origin"), but mechanically it's a peer repo. Even though it lets other repos push it around a bit and obeys commands like "change the branch to point to another commit", there are no commands to force it to delete the data.
- eviks 1y ago
  > Even though it lets other repos push it around So there is hierarchy > there are no commands to force it to delete the data. That's just the current state, the question was how git prevents "de facto" deletion on a server? How is it anti-git to ask the server to execute git garbage collection commands, for example?

tux3 1y ago

Git does forget, it has a gc mechanism specifically for forgetting. GitHub can't use the native git gc, and apparently doesn't have their own fork-aware and weird-cross-repo-merge-aware gc, so they might just not have built a way to track which commits are dangling. But that's not obvious at all.

lelandfe 1y ago
How to make git an elephant: https://donatstudios.com/yagni-git-gc https://donatstudios.com/yagni-git-gc
SillyUsername 1y ago
Ah right, so forking the codebase, then deleting the original repo forces git to forget all copies. Gotcha thanks for the enlightenment.

tossandthrow 1y ago

Git is not point in time backups. It is versioning. You are free to organize your version history as you fit, and you can certainly rewrite history. The only issue you might have is signed commits from collaborators, that you can not resign.

lloeki 1y ago
> and you can certainly rewrite history. But you can't coerce everyone in the world to remove all traces of the alternate history that was a thing before being rewritten. So while you can make git forget something in your local repo, you can't make git forget across the decentralised set of repos, which is part of git's core design. So in that sense, yes, git never forgets, by design.
deleted 1y ago
[deleted]