repeatable internal backend error (object could not be found)

[colemickens]

Description

I use this script to rebase a couple of my nixpkgs branches, to try to pre-cache my closure before I update locally and attempt a rebuild.

https://github.com/colemickens/nixcfg/blob/2e6fc42415717c237afecb0033afc90a93734153/.github/update.sh

Notably it tries to fetch as little as possible, tracks the branches, their "wip" branches. Resets the WIP branches to point at the same change as the non-wip branch, and then tries to rebase those branches onto their upstream equivalents.

so:

• jj bookmark set colemickens/wip/nixpkgs-unstable -r colemickens/nixpkgs-unstable
• jj rebase -b colemickens/wip/nixpkgs-unstable nixpkgs-unstable@nixos

roughly.

Today, that has been blowing up:

+ git remote add origin git@github.com:colemickens/nixpkgs
Initialized empty Git repository in /tmp/nixpkgs-ci/.git/
+ git config remote.origin.promisor true
+ git remote set-branches origin colemickens/wip/nixos-unstable colemickens/wip/nixpkgs-unstable colemickens/nixos-unstable colemickens/nixpkgs-unstable
+ git remote add nixos https://github.com/NixOS/nixpkgs.git
+ git config remote.nixos.promisor true
+ git remote set-branches nixos nixos-unstable nixpkgs-unstable
+ git fetch --filter=blob:none origin
From github.com:colemickens/nixpkgs
 * [new branch]                colemickens/wip/nixos-unstable -> origin/colemickens/wip/nixos-unstable
 * [new branch]                colemickens/wip/nixpkgs-unstable -> origin/colemickens/wip/nixpkgs-unstable
 * [new branch]                colemickens/nixos-unstable -> origin/colemickens/nixos-unstable
 * [new branch]                colemickens/nixpkgs-unstable -> origin/colemickens/nixpkgs-unstable
+ git fetch --filter=blob:none nixos
From https://github.com/NixOS/nixpkgs
 * [new branch]                nixos-unstable      -> nixos/nixos-unstable
 * [new branch]                nixpkgs-unstable    -> nixos/nixpkgs-unstable
 * [new tag]                   0.1                 -> 0.1
 * [new tag]                   0.13                -> 0.13
 * [new tag]                   0.14                -> 0.14
 * [new tag]                   0.2                 -> 0.2
 * [new tag]                   0.3                 -> 0.3
 * [new tag]                   0.4                 -> 0.4
 * [new tag]                   15.09-beta          -> 15.09-beta
 * [new tag]                   16.09-beta          -> 16.09-beta
 * [new tag]                   17.09-beta          -> 17.09-beta
 * [new tag]                   18.03-beta          -> 18.03-beta
 * [new tag]                   18.09-beta          -> 18.09-beta
 * [new tag]                   21.11-pre           -> 21.11-pre
 * [new tag]                   22.05-pre           -> 22.05-pre
 * [new tag]                   23.05-pre           -> 23.05-pre
 * [new tag]                   23.11-beta          -> 23.11-beta
 * [new tag]                   23.11-pre           -> 23.11-pre
 * [new tag]                   24.05-pre           -> 24.05-pre
 * [new tag]                   24.11-pre           -> 24.11-pre
 * [new tag]                   25.11-pre           -> 25.11-pre
 * [new tag]                   26.05-pre           -> 26.05-pre
 * [new tag]                   26.11-pre           -> 26.11-pre
 * [new tag]                   binary              -> binary
 * [new tag]                   black@2016-05-13    -> black@2016-05-13
 * [new tag]                   last-glibc-2.13     -> last-glibc-2.13
 * [new tag]                   release-16.03-start -> release-16.03-start
 * [new tag]                   v192                -> v192
 * [new tag]                   v206                -> v206
 * [new tag]                   v208                -> v208
+ jj git init --colocate
Done importing changes from the underlying Git repo.
Initialized repo in "."
+ jj bookmark track colemickens/wip/nixos-unstable --remote origin
Started tracking 1 remote bookmarks.
+ jj bookmark track colemickens/wip/nixpkgs-unstable --remote origin
Started tracking 1 remote bookmarks.
+ jj bookmark track colemickens/nixos-unstable --remote origin
Started tracking 1 remote bookmarks.
+ jj bookmark track colemickens/nixpkgs-unstable --remote origin
Started tracking 1 remote bookmarks.
+ jj bookmark set colemickens/wip/nixos-unstable -r colemickens/nixos-unstable --allow-backwards
Moved 1 bookmarks to wupnwrzq/0 26ad52e8 colemickens/nixos-unstable colemickens/wip/nixos-unstable* | (divergent) lunchmoney-mcp: init at 3.0.0
+ jj bookmark set colemickens/wip/nixpkgs-unstable -r colemickens/nixpkgs-unstable --allow-backwards
Moved 1 bookmarks to lqlvputu 7f45bbfb colemickens/nixpkgs-unstable colemickens/wip/nixpkgs-unstable* | tmux: fix darwin build
+ jj rebase -b colemickens/wip/nixos-unstable -d nixos-unstable@nixos
Rebased 3 commits to destination.
+ jj rebase -b colemickens/wip/nixpkgs-unstable -d nixpkgs-unstable@nixos
Internal error: Unexpected error from backend
Caused by:
1: Object 94c9cbd072e3d3911ac69ab9c263ceede0a4221d of type file not found
2: An object with id 94c9cbd072e3d3911ac69ab9c263ceede0a4221d could not be found
Error: Process completed with exit code 255.

An example run: https://github.com/colemickens/nixcfg/actions/runs/33415475347/job/99564955766

Steps to Reproduce the Problem

1. (see above)

Expected Behavior

1. The rebase either works, or gives a better error (maybe this is due to the weird way I'm cloning).

Actual Behavior

(see above)

Specifications

• Platform: x86_64-linux
• Version: 0.44.0