diff --git a/src/shared/bun-spawn-shim.test.ts b/src/shared/bun-spawn-shim.test.ts
index 06905bd76..238cfb1b1 100644
--- a/src/shared/bun-spawn-shim.test.ts
+++ b/src/shared/bun-spawn-shim.test.ts
@@ -59,6 +59,33 @@ describe("bun-spawn-shim", () => {
 
     expect(result.exitCode).toBe(0)
     expect(result.success).toBe(true)
-    expect(Buffer.from(result.stdout).toString().trim()).toBe("sync-ok")
+    expect(result.stdout).toBeDefined()
+    expect(Buffer.from(result.stdout!).toString().trim()).toBe("sync-ok")
+  })
+
+  test("#given spawnSync command #when it completes #then result.pid is a positive number", () => {
+    const result = spawnSync(["bun", "--version"], { stdout: "pipe", stderr: "pipe" })
+
+    expect(result.pid).toBeGreaterThan(0)
+  })
+
+  test("#given default stdio #when child reads stdin #then it does not hang waiting for input", async () => {
+    const proc = spawn(["cat"], { stdout: "pipe", stderr: "pipe" })
+
+    const exitCode = await proc.exited
+
+    expect(exitCode).toBe(0)
+  })
+
+  test("#given missing executable #when spawn invoked #then the error is surfaced to the caller", async () => {
+    let observedError: unknown
+    try {
+      const proc = spawn(["__omo-shim-missing-binary__"], { stdout: "pipe", stderr: "pipe" })
+      await proc.exited
+    } catch (error) {
+      observedError = error
+    }
+
+    expect(observedError).toBeDefined()
   })
 })
diff --git a/src/shared/bun-spawn-shim.ts b/src/shared/bun-spawn-shim.ts
index 158894f2d..de756793d 100644
--- a/src/shared/bun-spawn-shim.ts
+++ b/src/shared/bun-spawn-shim.ts
@@ -30,8 +30,8 @@ export interface SpawnedProcess {
 
 export interface SpawnSyncResult {
   readonly exitCode: number
-  readonly stdout: Buffer
-  readonly stderr: Buffer
+  readonly stdout: Buffer | undefined
+  readonly stderr: Buffer | undefined
   readonly success: boolean
   readonly pid: number
 }
@@ -81,20 +81,20 @@ function resolveCommand(cmdOrOpts: unknown, optsArg?: unknown): { cmd: string[];
 function resolveStdio(options: SpawnOptions): StdioTuple {
   if (options.stdio) return options.stdio
 
-  return [options.stdin ?? "pipe", options.stdout ?? "pipe", options.stderr ?? "pipe"]
+  return [options.stdin ?? "ignore", options.stdout ?? "pipe", options.stderr ?? "inherit"]
 }
 
 function wrapNodeProcess(proc: ReturnType<typeof nodeSpawn>): SpawnedProcess {
   let exitCode: number | null = null
-  const exited = new Promise<number>((resolve) => {
+  const exited = new Promise<number>((resolve, reject) => {
     proc.on("exit", (code) => {
       exitCode = code ?? 1
       resolve(exitCode)
     })
-    proc.on("error", () => {
+    proc.on("error", (error) => {
       if (exitCode === null) {
         exitCode = 1
-        resolve(1)
+        reject(error)
       }
     })
   })
@@ -158,9 +158,9 @@ export function spawnSync(cmdOrOpts: unknown, opts?: unknown): SpawnSyncResult {
 
   return {
     exitCode: result.status ?? 1,
-    stdout: result.stdout,
-    stderr: result.stderr,
+    stdout: result.stdout ?? undefined,
+    stderr: result.stderr ?? undefined,
     success: (result.status ?? 1) === 0,
-    pid: -1,
+    pid: result.pid ?? -1,
   }
 }
diff --git a/src/shared/spawn-with-windows-hide.ts b/src/shared/spawn-with-windows-hide.ts
index 872c8deeb..f6fec2a7e 100644
--- a/src/shared/spawn-with-windows-hide.ts
+++ b/src/shared/spawn-with-windows-hide.ts
@@ -75,7 +75,7 @@ export function spawnWithWindowsHide(command: string[], options: SpawnOptions):
   const proc = nodeSpawn(cmd, args, {
     cwd: options.cwd,
     env: options.env,
-    stdio: [options.stdin ?? "pipe", options.stdout ?? "pipe", options.stderr ?? "pipe"],
+    stdio: [options.stdin ?? "ignore", options.stdout ?? "pipe", options.stderr ?? "inherit"],
     windowsHide: true,
     shell: true,
   })