Git Core Message Reference
Version Control System — 50 error codes
Reference index of 50 built-in Git core messages with meanings, common causes, repository-state cues, and related context.
About Git Core
Git core messages are human-readable error and warning strings that Git produces during repository operations. Unlike HTTP status codes or OS exit codes, Git does not use numeric error identifiers — it relies on descriptive messages that explain the problem in the context of the operation that triggered it.
Git core messages cover five operational families: repository state issues (detached HEAD, unmerged paths, merge conflicts), push rejections (non-fast-forward, remote rejected, failed to push some refs), history warnings (divergent branches, unrelated histories), transport failures (authentication failed, could not resolve host, early EOF), and local metadata issues (index lock, corrupt index, bad config). Each family maps to a different stage of the Git workflow.
This collection documents 50 Git core messages, organised by operational family. Each entry explains what the message means, why Git produces it, which Git command triggered it, and how it relates to other Git states in the same workflow stage.
Showing 50 of 50 error codes
Git's internal object database is missing or corrupted.
The operating system denied Git's request for more RAM during a heavy operation.
Git detected corruption inside one of its compressed data bundles (packfiles).
An uncompressed file in Git's internal database has an invalid checksum or zero bytes.
The internal staging area database file has become corrupted.
Git paused the merge because it cannot automatically resolve overlapping changes.
Git aborted the merge to protect uncommitted changes in your working directory.
Git prevented a branch switch because it would overwrite unsaved changes in your working directory.
Git aborted the merge because it would overwrite untracked files in your working directory.
Git rejected your push because the remote repository contains commits missing from your local branch.
Git rejected your push because your branch is behind the remote, preventing a linear update.
The remote server actively refused to accept your pushed commits due to server-side rules.
Your local branch and the remote tracking branch have both received different commits.
The remote server could not locate the repository at the specified URL.
Git refused to run because the repository folder is owned by a different system user.
The remote server rejected your SSH connection because it did not recognize your SSH key.
Git failed to establish a data connection with the remote repository.
The server rejected your credentials during an HTTPS connection.
Your computer's DNS could not find the IP address for the remote repository's domain name.
The connection to the server was closed abruptly before Git finished transferring data.
The underlying HTTP client (cURL) failed to complete the network request.
Git received an End-Of-File signal before it finished downloading the expected repository data.
Git failed to save changes to the staging area due to a filesystem issue.
Git could not update a specific branch pointer because it is locked or corrupted.
Git stopped a rebase or cherry-pick because the commit conflicts with your current code.
Git found a submodule reference without a matching configuration entry.
Git successfully cloned the main repository but failed to download a required submodule.
Git could not check out a file because its path exceeds the OS length limit.
Git could not apply a patch file because the target code has changed too much.
Git refused to merge two projects because they do not share a common ancestor commit.
Your sparse-checkout rules excluded all files, leaving your working directory empty.
You have unresolved file conflicts preventing Git from completing the current operation.
You tried to add a remote named 'origin', but one with that name already exists.
Git does not know which remote branch should receive your pushed commits.
You checked out a specific commit, detaching your working directory from the branch history.
Git could not find the local branch you are trying to push.
Git could not find the file or directory you specified in your command.
The remote repository's default branch points to a branch that does not exist.
Git could not find the hidden directory required to execute commands.
Git cannot run because another Git process is currently modifying the repository.
Git cannot resolve 'HEAD' because the repository has no commits yet.
You tried to run a Git command while a previous rebase operation is still paused.
A local script (hook) executed by Git failed, forcing Git to abort the commit.
Git refused to create a commit because you haven't configured your name and email.
Git doesn't know whether you are referring to a branch name or a file path.
You attempted to create a Git tag using a name that is already taken.
Git cannot add a submodule because a Git repository already occupies that path.
Git cannot parse its configuration file due to a syntax error.
Git could not parse your input as a valid commit, branch, or file path.
Your local branch contains commits that have not yet been pushed to the remote server.
Frequently Asked Questions
Git was designed for terminal output and human readability. Instead of numeric codes, Git produces descriptive messages that explain the problem in the context of the command that triggered it. FixerCode organises these messages by operational family for structured reference.
A non-fast-forward rejection means the remote branch has commits the local branch does not have. Git blocks the update because accepting it could overwrite those commits, protecting shared branch history from accidental loss.
Detached HEAD means you checked out a specific commit instead of a branch, so your working directory is not attached to any branch. Unmerged paths means a merge or rebase is in progress and some files have conflicts that need resolution before the operation can continue.