fix: add Windows UTF-8 encoding environment variables for terminals

This fixes character corruption in terminal output when Windows systems use
non-UTF-8 encodings like GBK (code page 936).

Adds the following environment variables on Windows:
- PYTHONIOENCODING=utf-8: Force UTF-8 for Python stdin/stdout/stderr
- PYTHONUTF8=1: Enable Python 3.7+ UTF-8 mode
- RUBYOPT=-EUTF-8: Force Ruby to use UTF-8 encoding

Fixes #10709

src/integrations/terminal/ExecaTerminalProcess.ts

@@ -49,6 +49,15 @@ export class ExecaTerminalProcess extends BaseTerminalProcess {
 					// Ensure UTF-8 encoding for Ruby, CocoaPods, etc.
 					LANG: "en_US.UTF-8",
 					LC_ALL: "en_US.UTF-8",
+					// Windows-specific UTF-8 environment variables to prevent character corruption
+					// when the system uses non-UTF-8 encodings like GBK (code page 936)
+					// See: https://github.com/RooCodeInc/Roo-Code/issues/10709
+					// Python: Force UTF-8 encoding for stdin/stdout/stderr
+					PYTHONIOENCODING: "utf-8",
+					// Python 3.7+: Enable UTF-8 mode
+					PYTHONUTF8: "1",
+					// Ruby: Force UTF-8 encoding
+					RUBYOPT: "-EUTF-8",
 				},
 			})`${command}`
 

src/integrations/terminal/Terminal.ts

@@ -159,6 +159,18 @@ export class Terminal extends BaseTerminal {
 			VTE_VERSION: "0",
 		}
 
+		// Add Windows-specific UTF-8 environment variables to prevent character corruption
+		// when the system uses non-UTF-8 encodings like GBK (code page 936)
+		// See: https://github.com/RooCodeInc/Roo-Code/issues/10709
+		if (process.platform === "win32") {
+			// Python: Force UTF-8 encoding for stdin/stdout/stderr
+			env.PYTHONIOENCODING = "utf-8"
+			// Python 3.7+: Enable UTF-8 mode
+			env.PYTHONUTF8 = "1"
+			// Ruby: Force UTF-8 encoding
+			env.RUBYOPT = "-EUTF-8"
+		}
+
 		// Set Oh My Zsh shell integration if enabled
 		if (Terminal.getTerminalZshOhMy()) {
 			env.ITERM_SHELL_INTEGRATION_INSTALLED = "Yes"

src/integrations/terminal/__tests__/ExecaTerminalProcess.spec.ts

@@ -72,6 +72,22 @@ describe("ExecaTerminalProcess", () => {
 			)
 		})
 
+		it("should set Windows-specific UTF-8 environment variables", async () => {
+			await terminalProcess.run("echo test")
+			const execaMock = vitest.mocked(execa)
+			expect(execaMock).toHaveBeenCalledWith(
+				expect.objectContaining({
+					env: expect.objectContaining({
+						// Python UTF-8 encoding
+						PYTHONIOENCODING: "utf-8",
+						PYTHONUTF8: "1",
+						// Ruby UTF-8 encoding
+						RUBYOPT: "-EUTF-8",
+					}),
+				}),
+			)
+		})
+
 		it("should preserve existing environment variables", async () => {
 			process.env.EXISTING_VAR = "existing"
 			terminalProcess = new ExecaTerminalProcess(mockTerminal)
@@ -91,6 +107,19 @@ describe("ExecaTerminalProcess", () => {
 			expect(calledOptions.env.LANG).toBe("en_US.UTF-8")
 			expect(calledOptions.env.LC_ALL).toBe("en_US.UTF-8")
 		})
+
+		it("should override existing Python and Ruby encoding environment variables", async () => {
+			process.env.PYTHONIOENCODING = "latin-1"
+			process.env.PYTHONUTF8 = "0"
+			process.env.RUBYOPT = "-ELATIN-1"
+			terminalProcess = new ExecaTerminalProcess(mockTerminal)
+			await terminalProcess.run("echo test")
+			const execaMock = vitest.mocked(execa)
+			const calledOptions = execaMock.mock.calls[0][0] as any
+			expect(calledOptions.env.PYTHONIOENCODING).toBe("utf-8")
+			expect(calledOptions.env.PYTHONUTF8).toBe("1")
+			expect(calledOptions.env.RUBYOPT).toBe("-EUTF-8")
+		})
 	})
 
 	describe("basic functionality", () => {

src/integrations/terminal/__tests__/Terminal.getEnv.spec.ts

@@ -0,0 +1,65 @@
+// npx vitest run integrations/terminal/__tests__/Terminal.getEnv.spec.ts
+
+import { Terminal } from "../Terminal"
+
+describe("Terminal.getEnv", () => {
+	let originalPlatform: PropertyDescriptor | undefined
+
+	beforeAll(() => {
+		originalPlatform = Object.getOwnPropertyDescriptor(process, "platform")
+	})
+
+	afterAll(() => {
+		if (originalPlatform) {
+			Object.defineProperty(process, "platform", originalPlatform)
+		}
+	})
+
+	describe("common environment variables", () => {
+		it("should set VTE_VERSION to 0", () => {
+			const env = Terminal.getEnv()
+			expect(env.VTE_VERSION).toBe("0")
+		})
+
+		it("should set PAGER to empty string on Windows", () => {
+			Object.defineProperty(process, "platform", { value: "win32" })
+			const env = Terminal.getEnv()
+			expect(env.PAGER).toBe("")
+		})
+
+		it("should set PAGER to cat on non-Windows", () => {
+			Object.defineProperty(process, "platform", { value: "linux" })
+			const env = Terminal.getEnv()
+			expect(env.PAGER).toBe("cat")
+		})
+	})
+
+	describe("Windows UTF-8 encoding fix", () => {
+		beforeEach(() => {
+			Object.defineProperty(process, "platform", { value: "win32" })
+		})
+
+		it("should set PYTHONIOENCODING to utf-8 on Windows", () => {
+			const env = Terminal.getEnv()
+			expect(env.PYTHONIOENCODING).toBe("utf-8")
+		})
+
+		it("should set PYTHONUTF8 to 1 on Windows", () => {
+			const env = Terminal.getEnv()
+			expect(env.PYTHONUTF8).toBe("1")
+		})
+
+		it("should set RUBYOPT to -EUTF-8 on Windows", () => {
+			const env = Terminal.getEnv()
+			expect(env.RUBYOPT).toBe("-EUTF-8")
+		})
+
+		it("should not set Python/Ruby UTF-8 vars on non-Windows", () => {
+			Object.defineProperty(process, "platform", { value: "linux" })
+			const env = Terminal.getEnv()
+			expect(env.PYTHONIOENCODING).toBeUndefined()
+			expect(env.PYTHONUTF8).toBeUndefined()
+			expect(env.RUBYOPT).toBeUndefined()
+		})
+	})
+})