this greatly speeds up the time to run all tests, at the cost of slightly larger recompile times for individual tests.
this unfortunately adds the requirement that all tests are listed in `runner.rs` for the crate.
to avoid forgetting, i've added a new test that ensures the directory is in sync with the file.
## benchmarks
before this change, recompiling all tests took 32-50 seconds and running a single test took 3.5 seconds:
```
; hyperfine 'touch lib/src/lib.rs && cargo t --test test_working_copy'
Time (mean ± σ): 3.543 s ± 0.168 s [User: 2.597 s, System: 1.262 s]
Range (min … max): 3.400 s … 3.847 s 10 runs
```
after this change, recompiling all tests take 4 seconds:
```
; hyperfine 'touch lib/src/lib.rs ; cargo t --test runner --no-run'
Time (mean ± σ): 4.055 s ± 0.123 s [User: 3.591 s, System: 1.593 s]
Range (min … max): 3.804 s … 4.159 s 10 runs
```
and running a single test takes about the same:
```
; hyperfine 'touch lib/src/lib.rs && cargo t --test runner -- test_working_copy'
Time (mean ± σ): 4.129 s ± 0.120 s [User: 3.636 s, System: 1.593 s]
Range (min … max): 3.933 s … 4.346 s 10 runs
```
about 1.4 seconds of that is the time for the runner, of which .4 is the time for the linker. so
there may be room for further improving the times.
I originally thought this would be unavoidable, but I was wrong. "jj git clone"
doesn't implicitly create any local branch if git.auto-local-branch is off, and
that's fine because the detached HEAD state is normal in jj.
That being said, Git users would expect that the main/master branch exists.
Since importing the default branch is harmless, let's create and track it no
matter if git.auto-local-branch is off.
This will be the option to include non-tracking remote branches. We could add
more fine-grained filtering flags, but I think --all is good enough and easier
to remember.
This patch also updates many of the test outputs to include synchronized remote
branches. I think verbose outputs will help catch future bugs.
This replaces our existing mechanism of adding `/.jj/` to
`.git/info/exclude` by adding `*` to `.jj/.gitignore`, as suggested by
@ppwwyyxx. That simplifies the code quite a bit, and it avoids the
problem with `.git/info/exclude` not existing (it apparently doesn't
exist when the user uses
https://git-scm.com/docs/git-init#_template_directory).
Closes#2385.
We could fix do_git_clone() instead, but it seemed a bit weird that the
git_repo_path is relative to the store path which is unknown to callers.
Fixes#2374
AFAIK, we can't make HEAD detached in an empty Git repository, so we need
to temporarily switch to the new default branch before checking out.
Fixes#2047
They are shown next to the change and commit id, since they are other names the
commit can be referred by.
The description is separated from the branches by a ` | ` when there are
branches, so that one can tell the branches from the description without color.
The result looks like this: 
