In this guide, we'll explore the git fetch command with a focus on its --depth option. We will cover how --depth influences the behavior of git fetch, as well as other related options that modify the fetching process.
Fetch depth is typically used in shallow clones of repositories. For more information, see this guide on shallow cloning.
What is git fetch?
git fetch is a Git command used to download commits, files, and refs from a remote repository into your local repo, updating your remote-tracking branches. This command does not merge the changes into your current working branch unless explicitly done so with a subsequent merge command. It’s particularly useful before comparing the state of your local repository to that of the remote, as the command "fetches" all of the most recent changes.
Understanding the --depth option
The --depth option in git fetch is used to limit the number of commits Git downloads during the fetch process. This is known as a shallow fetch. It helps to reduce the amount of data transferred, speeding up the fetching process and decreasing the amount of storage used on your local machine.
Syntax and usage
The basic syntax for using --depth with git fetch is:
git fetch <remote> --depth=<n>
Where <remote> is the remote repository, and <n> is the number of commits you want to include in the fetch.
Examples
Fetching with limited depth: To fetch only the latest commit, you can run:
Terminalgit fetch origin --depth=1This command fetches only the latest commit from the default branch of the remote repository.
Deepening a shallow fetch: If you have previously performed a shallow fetch and now need more history, you can "deepen" the fetch:
Terminalgit fetch --deepen=5This adds 5 more commits to your history from the remote tracking branch.
Additional related commands
Fetching all branches with limited depth
If you want to fetch all branches but only with a limited depth:
git fetch --all --depth=1
This command fetches the latest commit from all branches but keeps the history shallow.
Fetching without tags
Sometimes, you might want to exclude tags when fetching to save time and space:
git fetch --no-tags
This command will still fetch all of the commit metadata from the repository, while ignoring tags.
Quiet and verbose fetch
You can control the verbosity of the git fetch output:
Quiet fetch: This minimizes the output to the terminal.
Terminalgit fetch --quietVerbose fetch: This provides detailed information about what the fetch command is doing.
Terminalgit fetch --verbose
When to use git fetch --depth
Using git fetch with the --depth option is particularly useful in continuous integration (CI) environments where you may only want to build and test the latest commits without waiting for the entire repository history to download.
It’s also beneficial when working on repositories with extensive commit histories where a full clone would be time-consuming and consume considerable bandwidth and storage.
In either case, it is best to use shallow fetching in addition to shallow cloning.
For further reading on the Git fetch command, see the official Git documentation.
