You are right. It wasn't the case for this exact bug. The source of this bug was probably the the design of the code editor that had function that duplicates line bound to a single keyboard shortcut right next to shortcut for saving file that every programmer uses roughly 1000 times a day. (What for? What's wrong with Home, Home, Shift+Down, Ctrl+C, Ctrl+V, Ctrl+V? Do you really need to duplicate single line in place that much so you need single key combination?).
However language that doesn't ignore indentation would make such error benign as duplicating the line wouldn't place code in completely different level of AST.
All programmers indent. Why so many languages happily ignore that?
I'm a huge fan of the Go compiler's general stubbornness. Have unused imports? Compile error. Have unreferenced vars? Compile error. Perhaps misleading indentation should be another compile error.
Pain the ass? You bet; it's a feature. Ignore the whiny kids who insist their 'flow' is broken by having to insert semicolons. Most software work is maintenance, not new code.
"All programmers indent. Why so many languages happily ignore that?"
I've encountered places where isolated breaks in indentation style radically increased readability. Unfortunately, I can't recall them well enough to reproduce here or know whether I'd now have a better solution. It surprised me at the time.
However language that doesn't ignore indentation would make such error benign as duplicating the line wouldn't place code in completely different level of AST.
All programmers indent. Why so many languages happily ignore that?