Our CI build started to fail due to browserstack-local throwing these errors:

Connecting BrowserStack local..
undefined:1
Tue Sep 01 2020 14:26:45 GMT+0000 (UTC) -- Container runtime environment detected
^

SyntaxError: Unexpected token T in JSON at position 0
    at JSON.parse (<anonymous>)
    at /root/<foo>/node_modules/browserstack-local/lib/Local.js:59:23
    at ChildProcess.exithandler (child_process.js:295:7)
    at ChildProcess.emit (events.js:196:13)
    at maybeClose (internal/child_process.js:1011:16)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:268:5)

As these randomly started, I suspect the BrowserStackLocal binary was updated with a broken version, as it doesn't seem to be pinned to a particular one. Manually starting the binary shows log messages in stdout, which probably shouldn't be there since browserstack-local expect valid JSON:

bash-4.4# /root/.browserstack/BrowserStackLocal --version 2>/dev/null
Tue Sep 01 2020 14:31:19 GMT+0000 (UTC) -- Container runtime environment detected
Tue Sep 01 2020 14:31:19 GMT+0000 (UTC) -- Attaching services to public interface
BrowserStack Local version 8.1

I'm running browserstack-local-nodejs v1.4.5 as v1.4.6 is broken as pointed out in 7e73b1f#r41945904, but manually patching v1.4.6 still shows the same issue.

This happens on Alpine Linux within a Docker container, hence the "Container runtime environment detected". The issue seems limited to container environments as running the v8.1 outside a container does not show the logs, and doesn't break browserstack-local.

In the future it would be great if the version of the BrowserStack binary could be pinned to a particular browserstack-local one, instead of the last version of the binary being randomly fetched as it is the case currently, causing CI builds to unexpectedly break.