Because Fossil separates the concept of “check-out directory” from “repository DB file,” it gives you the freedom to choose from several working styles. Contrast Git, where the two concepts are normally intermingled in a single working directory, which strongly encourages the “update in place” working style.
Multiple-Checkout Workflow
With Fossil, it is routine to have multiple check-outs from the same repository:
fossil clone https://example.com/repo /path/to/repo.fossil
mkdir -p ~/src/my-project/trunk
cd ~/src/my-project/trunk
fossil open /path/to/repo.fossil # implicitly opens “trunk”
mkdir ../release
cd ../release
fossil open /path/to/repo.fossil release
mkdir ../my-other-branch
cd ../my-other-branch
fossil open /path/to/repo.fossil my-other-branch
mkdir ../scratch
cd ../scratch
fossil open /path/to/repo.fossil abcd1234
mkdir ../test
cd ../test
fossil open /path/to/repo.fossil 2019-04-01
Now you have five separate check-out directories: one each for:
- trunk
- the latest tagged public release
- an alternate branch you’re working on
- a “scratch” directory for experiments you don’t want to do in the other check-out directories; and
- a “test” directory where you’re currently running a long-running test to evaluate a user bug report against the version as of last April Fool’s Day.
Each check-out operates independently of the others.
This multiple-checkouts working style is especially useful when Fossil stores source code in programming languages
where there is a “build” step that transforms source files into files
you actually run or distribute. Contrast a switch-in-place workflow,
where you have to rebuild all outputs from the source files
that differ between those versions whenever you switch versions. In the above model,
you switch versions with a “cd” command instead, so that you only have
to rebuild outputs from files you yourself change.
This style is also useful when a check-out directory may be tied up with
some long-running process, as with the “test” example above, where you
might need to run an hours-long brute-force replication script to tickle
a Heisenbug, forcing it to show itself. While that runs, you can
open a new terminal tab, “cd ../trunk”, and get back
to work.
Single-Checkout Workflows
Nevertheless, it is possible to work in a more typical Git sort of style, switching between versions in a single check-out directory.
The Idiomatic Fossil Way
The most idiomatic way is as follows:
fossil clone https://example.com/repo /path/to/repo.fossil
mkdir work-dir
cd work-dir
fossil open /path/to/repo.fossil
...work on trunk...
fossil update my-other-branch
...work on your other branch in the same directory...
Basically, you replace the cd commands in the multiple checkouts
workflow above with fossil up commands.
Opening a Repository by URI
In Fossil 2.12, we added a feature to simplify the single-worktree use case:
mkdir work-dir
cd work-dir
fossil open https://example.com/repo
Now you have “trunk” open in work-dir, with the repo file stored as
repo.fossil in that same directory.
Users of Git may be surprised that it doesn’t create a directory for you
and that you cd into it before the clone-and-open step, not after.
This is because we’re overloading the “open” command, which already had
the behavior of opening into the current working directory. Changing it
to behave like git clone would therefore make the behavior surprising
to Fossil users. (See our discussions if you want the full
details.)
Git-Like Clone-and-Open
In Fossil 2.14, we added a more Git-like alternative:
fossil clone https://fossil-scm.org/fossil
cd fossil
This results in a fossil.fossil repo DB file and a fossil/ working
directory.
Note that our clone URI behavior does not commingle the repo and
check-out, solving our major problem with the Git design.
If you want the repo to be named something else, adjust the URL:
fossil clone https://fossil-scm.org/fossil/fsl
That gets you fsl.fossil checked out into fsl/.
For sites where the repo isn’t served from a subdirectory like this, you
might need another form of the URL. For example, you might have your
repo served from dev.example.com and want it cloned as my-project:
fossil clone https://dev.example.com/repo/my-project
The /repo addition is the key: whatever comes after is used as the
repository name. See the docs for more details.