Using fixed git references¶

By default, tsrc sync synchronize projects using branches names.

Usually, one would use the same branch name for several git repositories, like this:

repos:
  - dest: foo
    url: git@gitlab.acme.com/your-team/foo
    branch: main

  - dest: bar
    url: git@gitlab.acme.com/your-team/bar
    branch: main

The assumption here is that foo and bar evolve "at the same time", so when the main branch of foo is updated, the main branch of bar much change too.

Sometimes though, this will not be the case. For instance, the main branch of the bar repo needs a specific, fixed version of foo in order to work.

Using a tag¶

One way to solve this is to push a v1.0 tag in the foo repository, and change the manifest too look like this:

repos:
  - dest: foo
    url: git@gitlab.acme.com/your-team/foo
-    branch: main
+    tag: v1.0

Using a sha1¶

An other way is to put the SHA1 of the relevant git commit in the foo repository in the manifest:

repos:
  - dest: foo
    url: git@gitlab.acme.com/your-team/foo
    branch: main
+    sha1: ad2b68539c78e749a372414165acdf2a1bb68203

Cloning repos using fixed refs¶

If the repo is configured with a tag, tsrc will call git clone --branch <tag> (which is valid)
Otherwise, tsrc will call git clone, followed by git reset --hard <sha1>

This is because you cannot tell git to use an arbitrary git reference as start branch when cloning (tags are fine, but sha1s are not).

This also explain why you need both branch and sha1 in the configuration.

Synchronizing repos using fixed refs¶

Here's what tsrc sync will do when trying to synchronize a repo configured with a fixed ref:

Run git fetch --tags --prune
Check if the repository is clean
If so, run git reset --hard <tag or sha1>