Error thrown "stdin.unref is not a function" during Parent instance initialization

[naz]

When running bthreads with BTHREADS_BACKEND = 'child_process'; configuration stdin.unref error pops up from time to time without clear reproduction scenario.

stdin.unref is not a function

----------------------------------------

TypeError: stdin.unref is not a function
    at Parent._init (/home/REDACTED/node_modules/bthreads/lib/process/parent.js:129:11)
    at new Parent (/home/REDACTED/node_modules/bthreads/lib/process/parent.js:81:10)
    at Object.<anonymous> (/home/REDACTED/node_modules/bthreads/lib/process/thread.js:15:16)
    at Module._compile (internal/modules/cjs/loader.js:1138:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1158:10)
    at Module.load (internal/modules/cjs/loader.js:986:32)
    at Function.Module._load (internal/modules/cjs/loader.js:879:14)
    at Module.require (internal/modules/cjs/loader.js:1026:19)
    at require (internal/modules/cjs/helpers.js:72:18)
    at Object.<anonymous> (/home/REDACTED/node_modules/bthreads/lib/process/index.js:10:20)

Environment details:

• Node v12.18.0
• [email protected]
• used through bree@4.0.0 job scheduling module
• worker threads are initialized this way in bree

@chjj would appreciate any tips on tackling this and thanks for all your work on this project!

Notes:

• possibly linked to b5214a2 and worker: only unref port for stdin if we ref’ed it before nodejs/node#28153