> jj merge exists but it's not obvious which revisions you are supposed to pass to it
I don't think I understand your confusion. `jj merge` is essentially like Git merge, except that you also normally pass the current commit as one of the revisions. For example, you could write `jj merge @ main` to make a merge commit with the working copy[1] and the `main` branch. Feel free to open a GitHub discussion or drop by the Discord channel to discuss more.
> jj log doesn't even seem to be able to update the HEAD for the parent branch
`git log`/`jj log` are non-mutating operations, so why would you expect that they can update `HEAD`/branches?
[1]: In my workflows, I typically use `@-` instead of `@` in this situation because I consider the working copy commit to contain "uncommitted" changes, but there is a significant complement of users who primarily use `@`, so it depends on your workflow.
I don't think I understand your confusion. `jj merge` is essentially like Git merge, except that you also normally pass the current commit as one of the revisions. For example, you could write `jj merge @ main` to make a merge commit with the working copy[1] and the `main` branch. Feel free to open a GitHub discussion or drop by the Discord channel to discuss more.
> jj log doesn't even seem to be able to update the HEAD for the parent branch
`git log`/`jj log` are non-mutating operations, so why would you expect that they can update `HEAD`/branches?
[1]: In my workflows, I typically use `@-` instead of `@` in this situation because I consider the working copy commit to contain "uncommitted" changes, but there is a significant complement of users who primarily use `@`, so it depends on your workflow.