Bug type

Regression (worked before, now fails)

Beta release blocker

No

Summary

Running bun openclaw.mjs crashes immediately with Cannot find module './dist/warning-filter.js' on v2026.3.22 and later. The isDirectModuleNotFoundError function in openclaw.mjs relies on Node-specific error properties (err.url, absolute path in err.message) that Bun does not provide, causing the optional warning-filter import to throw instead of being silently skipped.

Steps to reproduce

git clone https://github.com/openclaw/openclaw.git && cd openclaw
git checkout v2026.4.19-beta.2   # or any version >= v2026.3.22
pnpm install && pnpm build && pnpm ui:build
bun openclaw.mjs --version

Expected behavior

Prints version and exits, as it did on v2026.3.13-1 and earlier.

Actual behavior

error: Cannot find module './dist/warning-filter.js' from '/path/to/openclaw/openclaw.mjs'

Bun v1.3.10 (Linux x64)

OpenClaw version

v2026.3.22 through v2026.4.19-beta.2 (current)

Operating system

Ubuntu 24.04 (WSL2)

Install method

pnpm dev (from source)

Model

N/A (crashes before model resolution)

Provider / routing chain

N/A

Logs, screenshots, and evidence

Regression introduced by commit 092afc850d ("Bootstrap: report nested entry import misses"), first included in v2026.3.22. Last known good version: v2026.3.13-1.

The commit replaced isModuleNotFoundError (checks err.code === "ERR_MODULE_NOT_FOUND", works on both Node and Bun) with isDirectModuleNotFoundError, which checks:

1. err.url === expectedUrl.href — Node sets err.url, Bun does not (undefined)
2. err.message contains the resolved absolute path — Node uses absolute paths, Bun uses the original relative specifier

Both checks fail on Bun, so the catch block falls through to throw err.

Bun's ResolveMessage error object exposes a structured err.specifier property containing the original import specifier, which can be matched directly:

// Node ERR_MODULE_NOT_FOUND:
{ code: "ERR_MODULE_NOT_FOUND", url: "file:///abs/path/warning-filter.js", message: "Cannot find module '/abs/path/warning-filter.js' ..." }

// Bun ResolveMessage:
{ code: "ERR_MODULE_NOT_FOUND", specifier: "./dist/warning-filter.js", referrer: "/abs/path/openclaw.mjs", message: "Cannot find module './dist/warning-filter.js' ..." }

Suggested fix — add a Bun-compatible check using err.specifier (symmetric with the existing err.url check for Node):

--- a/openclaw.mjs
+++ b/openclaw.mjs
@@ -56,10 +56,16 @@ const isDirectModuleNotFoundError = (err, specifier) => {
   }

   const expectedUrl = new URL(specifier, import.meta.url);
+  // Node sets err.url to the file URL of the missing module.
   if ("url" in err && err.url === expectedUrl.href) {
     return true;
   }

+  // Bun sets err.specifier to the original import specifier.
+  if ("specifier" in err && err.specifier === specifier) {
+    return true;
+  }
+
   const message = "message" in err && typeof err.message === "string" ? err.message : "";
   const expectedPath = fileURLToPath(expectedUrl);
   return (

Verified on Bun 1.3.10: bun openclaw.mjs --version and bun openclaw.mjs --help both work after the fix. Node behavior unchanged.

Impact and severity

• Affected: all users running OpenClaw from source with Bun
• Severity: blocks Bun runtime entirely (immediate crash on startup)
• Frequency: 100% reproducible on every Bun invocation
• Consequence: Bun cannot be used to run the gateway or any CLI command since v2026.3.22, despite README stating "Bun is optional for running TypeScript directly"

Additional information

Last known good: v2026.3.13-1. First known bad: v2026.3.22. Happy to open a PR if the approach looks good.