[BUG] Golang replace calls more often than not fail (tabs vs spaces?)

Environment

• Platform (select one):
• [x] Anthropic API
• [ ] AWS Bedrock
• [ ] Google Vertex AI
• [ ] Other: <!-- specify -->
• Claude CLI version: <!-- output of claude --version -->
• Operating System: MacOS Sequoia
• Terminal: Tmux in Ghostty

Bug Description

Claude code seems to struggle with find and replace in golang functions. It's very common for it to try 20 different ways to replace a code. the sed paths tend to work, also sometimes it has to go all the way to a hexdump to make the edit.

The edits work flawlessly in typescript though. My best random guess is that it fails because go defaults to tab based indentation instead of n-spaces.

Let me know if you all need more to reproduce, happy to setup a demo repo.

A short sample here:

⏺ Update(src/server/bundleServer/bundle_server.go)…
  ⎿  File has been modified since read, either by the user or by a linter. Read it again before
     attempting to write it.

⏺ Read(src/server/bundleServer/bundle_server.go)…
  ⎿  Read 50 lines (ctrl+r to expand)

⏺ I see the file has been updated already. Let me add some debug logging to the existing code:

⏺ Update(src/server/bundleServer/bundle_server.go)…
  ⎿  String to replace not found in file.

⏺ Let me check the file again to see how much it has changed:

⏺ Read(src/server/bundleServer/bundle_server.go)…
  ⎿  Read 391 lines (ctrl+r to expand)

⏺ The file has been significantly modified since our original implementation. I'll add tasteful
  logging to help diagnose issues when files are missed:

⏺ Update(src/server/bundleServer/bundle_server.go)…
  ⎿  String to replace not found in file.

⏺ The file seems to be continuously changing. Let me check a smaller section to ensure I have the
  current state:

⏺ Bash(sed -n "65,85p"                                                                       …
      api/src/server/bundleServer/bundle_server.go)

Update(src/server/bundleServer/bundle_server.go)…
  ⎿  String to replace not found in file.

  Bash(grep -A3 -B2 "// If nothing found" src/server/bundleServer/bundle_server.go)…