diff --git a/src/cli/config-manager/bun-install.test.ts b/src/cli/config-manager/bun-install.test.ts
new file mode 100644
index 000000000..e3b007f7d
--- /dev/null
+++ b/src/cli/config-manager/bun-install.test.ts
@@ -0,0 +1,96 @@
+import { afterEach, beforeEach, describe, expect, it, spyOn } from "bun:test"
+
+import * as loggerModule from "../../shared/logger"
+import * as spawnWithWindowsHideModule from "../../shared/spawn-with-windows-hide"
+import { resetConfigContext } from "./config-context"
+import { runBunInstallWithDetails } from "./bun-install"
+
+function createProc(
+  exitCode: number,
+  output?: { stdout?: string; stderr?: string }
+): ReturnType<typeof spawnWithWindowsHideModule.spawnWithWindowsHide> {
+  return {
+    exited: Promise.resolve(exitCode),
+    exitCode,
+    stdout: output?.stdout ? new Blob([output.stdout]).stream() : undefined,
+    stderr: output?.stderr ? new Blob([output.stderr]).stream() : undefined,
+    kill: () => {},
+  } satisfies ReturnType<typeof spawnWithWindowsHideModule.spawnWithWindowsHide>
+}
+
+describe("runBunInstallWithDetails", () => {
+  beforeEach(() => {
+    process.env.OPENCODE_CONFIG_DIR = "/test/opencode"
+    resetConfigContext()
+  })
+
+  afterEach(() => {
+    resetConfigContext()
+    delete process.env.OPENCODE_CONFIG_DIR
+  })
+
+  it("inherits install output by default", async () => {
+    // given
+    const spawnSpy = spyOn(spawnWithWindowsHideModule, "spawnWithWindowsHide").mockReturnValue(createProc(0))
+
+    try {
+      // when
+      const result = await runBunInstallWithDetails()
+
+      // then
+      expect(result).toEqual({ success: true })
+      const [_, options] = spawnSpy.mock.calls[0] as Parameters<typeof spawnWithWindowsHideModule.spawnWithWindowsHide>
+      expect(options.stdout).toBe("inherit")
+      expect(options.stderr).toBe("inherit")
+    } finally {
+      spawnSpy.mockRestore()
+    }
+  })
+
+  it("pipes install output when requested", async () => {
+    // given
+    const spawnSpy = spyOn(spawnWithWindowsHideModule, "spawnWithWindowsHide").mockReturnValue(createProc(0))
+
+    try {
+      // when
+      const result = await runBunInstallWithDetails({ outputMode: "pipe" })
+
+      // then
+      expect(result).toEqual({ success: true })
+      const [_, options] = spawnSpy.mock.calls[0] as Parameters<typeof spawnWithWindowsHideModule.spawnWithWindowsHide>
+      expect(options.stdout).toBe("pipe")
+      expect(options.stderr).toBe("pipe")
+    } finally {
+      spawnSpy.mockRestore()
+    }
+  })
+
+  it("logs captured output when piped install fails", async () => {
+    // given
+    const spawnSpy = spyOn(spawnWithWindowsHideModule, "spawnWithWindowsHide").mockReturnValue(
+      createProc(1, {
+        stdout: "resolved 10 packages",
+        stderr: "network error",
+      })
+    )
+    const logSpy = spyOn(loggerModule, "log").mockImplementation(() => {})
+
+    try {
+      // when
+      const result = await runBunInstallWithDetails({ outputMode: "pipe" })
+
+      // then
+      expect(result).toEqual({
+        success: false,
+        error: "bun install failed with exit code 1",
+      })
+      expect(logSpy).toHaveBeenCalledWith("[bun-install] Captured output from failed bun install", {
+        stdout: "resolved 10 packages",
+        stderr: "network error",
+      })
+    } finally {
+      logSpy.mockRestore()
+      spawnSpy.mockRestore()
+    }
+  })
+})
diff --git a/src/cli/config-manager/bun-install.ts b/src/cli/config-manager/bun-install.ts
index 6b3225547..1f1cfc97a 100644
--- a/src/cli/config-manager/bun-install.ts
+++ b/src/cli/config-manager/bun-install.ts
@@ -1,9 +1,30 @@
 import { getConfigDir } from "./config-context"
+import { log } from "../../shared/logger"
 import { spawnWithWindowsHide } from "../../shared/spawn-with-windows-hide"
 
 const BUN_INSTALL_TIMEOUT_SECONDS = 60
 const BUN_INSTALL_TIMEOUT_MS = BUN_INSTALL_TIMEOUT_SECONDS * 1000
 
+type BunInstallOutputMode = "inherit" | "pipe"
+
+interface RunBunInstallOptions {
+  outputMode?: BunInstallOutputMode
+}
+
+interface BunInstallOutput {
+  stdout: string
+  stderr: string
+}
+
+declare function setTimeout(callback: () => void, delay?: number): number
+declare function clearTimeout(timeout: number): void
+
+type ProcessOutputStream = ReturnType<typeof spawnWithWindowsHide>["stdout"]
+
+declare const Bun: {
+  readableStreamToText(stream: NonNullable<ProcessOutputStream>): Promise<string>
+}
+
 export interface BunInstallResult {
   success: boolean
   timedOut?: boolean
@@ -15,21 +36,54 @@ export async function runBunInstall(): Promise<boolean> {
   return result.success
 }
 
-export async function runBunInstallWithDetails(): Promise<BunInstallResult> {
+function readProcessOutput(stream: ProcessOutputStream): Promise<string> {
+  if (!stream) {
+    return Promise.resolve("")
+  }
+
+  return Bun.readableStreamToText(stream)
+}
+
+function logCapturedOutputOnFailure(outputMode: BunInstallOutputMode, output: BunInstallOutput): void {
+  if (outputMode !== "pipe") {
+    return
+  }
+
+  const stdout = output.stdout.trim()
+  const stderr = output.stderr.trim()
+  if (!stdout && !stderr) {
+    return
+  }
+
+  log("[bun-install] Captured output from failed bun install", {
+    stdout,
+    stderr,
+  })
+}
+
+export async function runBunInstallWithDetails(options?: RunBunInstallOptions): Promise<BunInstallResult> {
+  const outputMode = options?.outputMode ?? "inherit"
+
   try {
     const proc = spawnWithWindowsHide(["bun", "install"], {
       cwd: getConfigDir(),
-      stdout: "inherit",
-      stderr: "inherit",
+      stdout: outputMode,
+      stderr: outputMode,
     })
 
-    let timeoutId: ReturnType<typeof setTimeout>
+    const outputPromise = Promise.all([readProcessOutput(proc.stdout), readProcessOutput(proc.stderr)]).then(
+      ([stdout, stderr]) => ({ stdout, stderr })
+    )
+
+    let timeoutId: ReturnType<typeof setTimeout> | undefined
     const timeoutPromise = new Promise<"timeout">((resolve) => {
       timeoutId = setTimeout(() => resolve("timeout"), BUN_INSTALL_TIMEOUT_MS)
     })
     const exitPromise = proc.exited.then(() => "completed" as const)
     const result = await Promise.race([exitPromise, timeoutPromise])
-    clearTimeout(timeoutId!)
+    if (timeoutId) {
+      clearTimeout(timeoutId)
+    }
 
     if (result === "timeout") {
       try {
@@ -37,6 +91,10 @@ export async function runBunInstallWithDetails(): Promise<BunInstallResult> {
       } catch {
         /* intentionally empty - process may have already exited */
       }
+
+      await proc.exited
+      logCapturedOutputOnFailure(outputMode, await outputPromise)
+
       return {
         success: false,
         timedOut: true,
@@ -44,7 +102,11 @@ export async function runBunInstallWithDetails(): Promise<BunInstallResult> {
       }
     }
 
+    const output = await outputPromise
+
     if (proc.exitCode !== 0) {
+      logCapturedOutputOnFailure(outputMode, output)
+
       return {
         success: false,
         error: `bun install failed with exit code ${proc.exitCode}`,