How do I know the state of a repo (status doesn't show much)?

[joyously]

Apparently I need more information from jj, but I don't know what to search for.
I cloned the jj repo sometime last year, and I thought I had fetched updates (maybe not). When I look at the file dates, they all say October 18, 2024. So today I wanted to search for something and did a fetch. But I don't think it fetched anything since all the file dates remain the same. (The Cargo.lock file says January -- I think I did cargo update.)
Anyway, here is the meager output I got. How can a user determine if their repo matches the remote, especially an unfamiliar one?

_working/contrib/jj$ jj git fetch
bookmark: gh-readonly-queue/main/pr-5682-148e4235fd726b655eec31d6baebaaf05c5b4776@origin [new] untracked
_working/contrib/jj$ git pull
fatal: not a git repository (or any parent up to mount point /media)
Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).
_working/contrib/jj$ jj st
Working copy changes:
M Cargo.lock
Working copy : spvssyqn b03d7fa9 (no description set)
Parent commit: uupoyoyx 0eb4fe83 text_util: add functions to truncate labeled text

[jennings]

Fetching updates branches but doesn’t move the working copy. After fetching, you can move the working copy with:

jj new trunk()   # or main, master, etc.

If your working copy has changes, you could instead jj rebase -d trunk() to bring your changes with you.

If you’re not sure if you’re tracking the branch in question, you can use the remote tracking branch: jj new main@origin

[joyously]

When you say "updates branches", are you referring to an internal update that would not be reflected in the files?
I didn't intentionally make any changes. I guess cargo update did, though I simply wanted to get the latest versions of dependencies for various projects while I was online.
I don't expect to have to do any commands to change the repo, if all I wanted to do was read the code and test some things. I just need a way to see more clearly the status of the repo.
I don't know if I'm tracking anything or not (shouldn't that show in status?) since all I did was clone the repo a few months ago.

[jennings]

When you say "updates branches", are you referring to an internal update that would not be reflected in the files?

That’s right.

I like analogies, but the best one I can think of is playing chess over mail:

• Your equipment consists of a board and a ledger of moves made this game. The board is the working copy, the ledger is the commit history, and together they are your "repository".
• You and your opponent each have a board and ledger. Yours is your local repository, theirs is the remote repository.
• Fetching is like receiving a turn from your opponent:
  • You’ve recorded their move in the ledger (updated bookmarks)
  • But you haven't yet updated your board, so your board doesn't match your opponent's yet.

Updating your board with the latest move is like running jj new trunk(). After doing so, your board (working copy) matches your opponents' (the remote repo).

I hope this makes sense, I came up with this analogy on the fly.

I don't know if I'm tracking anything or not (shouldn't that show in status?) since all I did was clone the repo a few months ago.

Tracking or not is a property of the remote bookmark like main@origin. You could be tracking a dozen different bookmarks, which one should jj status show you? With git, you usually have checked out a specific branch, so git status can tell you whether that commit is ahead or behind its remote counterpart. But jj doesn't have a current branch/bookmark.

jj status is primarily showing you the status of the working copy commit. Whether it contain any changes, which files conflicted, and which commit it is.

[joyously]

jj status is primarily showing you the status of the working copy commit.

That is definitely not sufficient when it could change with each command. Is there some command to re-orient yourself after you've been away awhile?
Since some commands update files (rebasing descendants), it seems like fetch would. It is unintuitive to have to do another command. How is a user supposed to examine a repo without changing anything?

[jennings]

To figure out how outdated my working copy is, I would want to know where I am in relationship to the trunk. The default jj log output will show me that, but to filter it down to the bare minimum, I could do this:

jj log -r 'trunk()..@ | trunk() | fork_point(@ | trunk())'

This will show me:

• trunk()..@ - Everything leading up to the working copy that's not yet in the trunk.
• trunk() - The trunk itself
• fork_point(@ | trunk()) - The common ancestor between the working copy and the trunk.

This will show a graph that shows everything leading up to my working copy, and how far behind I am from the trunk. For example, this is what it looks like if I run this in my jj repository:

> jj log -r 'trunk()..@ | trunk() | fork_point(@ | trunk())'
@  unnmrsnm [email protected] 2 minutes ago default@ 356aef4f
│  (empty) (no description set)
│
│ ◆  rxtultxt [email protected] 3 hours ago main* 4a47a4fc
│ │  commit: Add `commit.is_hidden(repo)`
│ │
│ ~  (elided revisions)
├─╯
◆  pxksllrl [email protected] 3 days ago git_head() 768ec3b9
│  github: s/build-binaries/binaries/

From this, I can see that my working copy is empty, I branched off of the trunk 3 days ago (the date on pxksllrl), and the trunk was last updated 3 hours ago.

Since I'm not in the middle of anything, I can just jj new trunk() to update my working copy to the latest that's in main. If I had work in progress, I could jj rebase -d trunk() to rebase the branch I'm working on onto the latest main.

[joyously]

That seems like a lot to have to know and do in order to start to see what is going on.
Again,

How is a user supposed to examine a repo without changing anything?

Breezy has a command called missing, with description "Show unmerged/unpulled revisions between two branches."