Line CLI's file edit failed. Why?

An edit replaces an exact snippet. It fails when:

• The snippet isn't in the file (the file changed, or whitespace differs).
• The snippet appears more than once.
• Another agent changed the file since this agent read it (conflict check).

Line matches small indentation slips automatically, and a failed edit shows the closest lines of the file so the agent can fix its next try. Usually it recovers on its own.

If it keeps failing, ask it to re-read the file first, or to rewrite the specific function.