[BUG] The edit tool doesn't understand how to write with tab indentation

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

The Edit tool in Claude Code can't match tab characters in old_string. Read renders them fine, but Edit's string matching silently fails on any tab-indented file. Forces full file rewrites as a workaround. This is a basic find-and-replace -- tabs shouldn't break it.

This has been happening to me all week, at least it feels like it. Maybe the last four days.

⏺ Update(agent/src/tui/keys/theme.ts)                                                                                                                                                   
  ⎿  Error editing file                                                             
                                                                                                                                                                                        
⏺ Bash(cat -A /Users/shaneholloman/git/sources/uicnz/aria/agent/src/tui/keys/theme.ts | sed -n '111,124p')                                                                              
  ⎿  cat: illegal option -- A                                                                                                                                                           
     usage: cat [-belnstuv] [file ...]                                                                                                                                                  
                                               
⏺ Bash(sed -n '111,124p' /Users/shaneholloman/git/sources/uicnz/aria/agent/src/tui/keys/theme.ts | cat -vet)                                                                            
  ⎿  ^I^I^I^I{$                                                                                                                                                                         
     ^I^I^I^I^Itype: 'hotkey',$                                                                                                                                                         
     ^I^I^I^I^Ihotkeys: ['Enter'],$                                                                                                                                                     
     … +11 lines (ctrl+o to expand)                                                                                                                                                     
                                                                                                                                                                                        
⏺ All tabs. The Read tool rendered them as spaces. Let me use the exact tab characters.
                                                                                                                                                                                        
⏺ Bash(sed -i '' '/\t\t\t\t\t\thotkeys: \['\''Enter'\''\],/{                                                                                                                            
      N;N;N;N;N;N;N…)
  ⎿  (No output)                                                                                                                                                                        
                                                                                    
⏺ Read 1 file (ctrl+o to expand)     

What Should Happen?

Should be tabs aware.

Error Messages/Logs

none

Steps to Reproduce

Simply have Claude try to edit a TypeScript file that uses tabs.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Not sure since these versions move so fast.

Claude Code Version

But my version is this: 2.1.42

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_