[BUG]bash tool fails on Windows due to unsupported export command in environment variable setup #16434

Description

When using the bash tool on Windows to execute commands (e.g., git status), the tool automatically prepends export statements to set environment variables. However, Windows shells do not support the export command, causing all commands to fail.

Plugins

No response

OpenCode version

1.2.20

Steps to reproduce

1. Open a project on Windows system
2. Execute any bash command, for example:

   {
     "command": "git status",
     "description": "Check git status"
   }

3. The tool actually executes:
   export CI=true DEBIAN_FRONTEND=noninteractive GIT_TERMINAL_PROMPT=0 ... && git status
4. Error occurs: 'export' is not recognized as an internal or external command

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Operating System

windows11

Terminal

Windows terminal