merge conflict
This occurs when the same part of a file is modified in two different ways by two people, and the version control system cannot decide on its own which version to keep.
In plain terms
Imagine that you and a colleague each receive a copy of the same contract draft. You rewrite the third paragraph, and your colleague rewrites the same paragraph but differently. When the two copies must be merged, someone must decide: yours stays, theirs, or a mix of both. This is the situation of a merge conflict.
In software development, version control systems (most commonly Git) keep track of code. This allows many people to work in parallel, each on their own "branch." Merging work is mostly automatic: if you modified the beginning of a file and someone else the end, the system puts it together without issue.
A conflict occurs when two changes affect the same or directly adjacent lines in different ways, or when one party deleted something the other edited. In such cases, the system halts and asks a human or an agent to decide. This is not a bug but a safeguard: the machine does not guess and does not silently overwrite anyone's work.
It entered AI terminology because coding agents often work in parallel on the same project. The more agents writing code simultaneously, the more frequently their changes conflict.
How it works
- Two tasks start from the same initial state: for example, two developers or two coding agents begin modifying on separate branches.
- During merging, the version control system compares three versions: the common starting point and the two modified ones. Where only one party made changes, the change is automatically adopted.
- Where both parties edited the same lines but differently, the system stops and places the two versions under each other between markers in the file. If they accidentally wrote exactly the same thing, there is no conflict.
- Someone decides what the final text should be: one version, the other, or a new one that preserves both intentions.
- The resolved file is marked as complete, tests are run, and the merge is finalized.
An everyday example
Ask two coding agents to work on your webshop simultaneously. Both overwrite the same line of code for the cart button: one changes the button color, the other the label. When you try to merge the two changes, the system flags the conflict, and the merge remains on hold until someone decides on the final version. If the two agents had modified distant lines of the same file, the system would have merged them automatically.
Who is affected
A common misconception
Limits and risks
- The version control system only detects textual overlaps: two changes can still break the program together even if they affect different lines, and the system does not signal a conflict.
- Poor resolution can silently erase someone's work, so it is always worth testing and reviewing the result afterward.
- AI agents can resolve conflicts, but they do not always understand the intent behind two modifications, so important decisions must be reviewed by a human.
- The longer a branch lives separately, the more and the harder the conflicts that pile up, so frequent, small merges pay off better.
Similar, but not the same
- programhiba (bug) – A bug is a program's faulty operation, whereas a conflict is merely an undecided issue between two versions that emerges during merging, before it is finalized.
- merge – Merging is the operation of combining, which usually proceeds smoothly; a conflict is the rarer case where someone must make a decision.
- build hiba – A build error means a runnable program cannot be created from the code, which can occur even after a successful, conflict-free merge.
Related concepts
version control, software development, collaborative coding
conflict resolution, three-way merge
A brief history
The concept of conflict is as old as version control systems that allow parallel work. It was commonplace even in pre-Git systems like CVS and Subversion. Git, created by Linus Torvalds in 2005, made it truly widespread because it is built on frequent branching and merging.
Where things stand
By the end of 2026, this is a common, well-known phenomenon in software development, with developer tools providing built-in resolution interfaces. Due to parallel coding agents, resolution has come back to the forefront, and agents increasingly perform resolutions themselves under human supervision.
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Also known as
merge conflict · merge konfliktus · merge conflict · merge conflict · merge conflict · Git conflict · git conflict · conflict
Sources
This entry was machine-edited and has undergone machine expert review; the “In the news” section updates automatically from Agent Age stories.