I have reproduced the issue on the latest CLI version.
Yes, I am on the latest version
I have searched existing posts and this report is not a duplicate.
Yes, this isn’t a duplicate
In which of these areas are you experiencing a problem?
Extension
Expected behavior
App successfully deploys
Actual behavior
On @shopify/cli@3.94.0, both commands fail at the Bundle UI Extension step for the web_pixel_extension only. All other extension types in the same app build and deploy correctly.
The web_pixel_extension’s bundle step now resolves source and destination to the same path (extensions//dist), and the .shopify/deploy-bundle//dist/.js file is never produced — so buildValidation’s subsequent getFileSize(outputPath) call throws ENOENT.
Reproduction steps
Any Shopify app containing a web_pixel_extension reproduces this deterministically.
Clone an app that has a web pixel extension (or scaffold one with shopify app generate extension --type=web_pixel_extension).
From the project root:
npx -y @shopify/cli@3.93.2 app build # success
npx -y @shopify/cli@3.94.0 app build # fails
Same pattern with app deploy against a real org/app:
npx -y @shopify/cli@3.93.2 app deploy # success
npx -y @shopify/cli@3.94.0 app deploy # fails
Verbose output
│ Build step "Bundle UI Extension" failed: Source and destination must not │
│ be the same. │
│ │
│ To investigate the issue, examine this stack trace: │
│ at (…/node_modules/@shopify/cli/dist/chunk-DEW5QFGH.js:2) │
│ at processTicksAndRejections (node:internal/process/task_queues:90) │
╰──────────────────────────────────────────────────────────────────────────────╯
"error_message": "Build step \"Bundle UI Extension\" failed: Source and destination must not be the same.",
"cli_version": "3.94.0",
"node_version": "23.6.1",
"uname": "darwin arm64",
"app_extensions_breakdown": "{\"function\":1,\"web_pixel_extension\":1,\"ui_extension\":7,\"flow_trigger\":1,\"theme\":1,\"flow_action\":1,\"checkout_post_purchase\":1}",
CI variant of the same bug (shopify app deploy --verbose on Linux):
Build step "Bundle UI Extension" failed: ENOENT: no such file or directory,
stat '/builds/loopreturns/applications/loop-shopify-app/.shopify/deploy-bundle/8e85653a-…/dist/loop-web-pixel.js'
at async DCe (.../@shopify/cli/dist/chunk-DEW5QFGH.js:249)
at async buildValidation (web_pixel_extension)
Operating system
Mac OS
CLI version
3.94.0
Shell
zsh
Nodejs version
23.6.1
What language and version are you using in your application?
javascript/typescript