process exits silently with --experimental-modules and inexistent entry point

[targos]

Repro: node --experimental-modules xxx.mjs where xxx.mjs does not exist.

Expected: A module not found error with exit code of 1.
In 8.5.0, we had:

$ node --experimental-modules xxx.mjs
(node:15121) ExperimentalWarning: The ESM module loader is experimental.
Error: module /home/mzasso/test/abc/xxx.mjs not found
    at module.exports (internal/loader/search.js:16:12)
    at resolveRequestUrl (internal/loader/resolveRequestUrl.js:81:13)
    at Loader.import (internal/loader/Loader.js:61:27)
    at Function.Module._load (module.js:462:27)
    at Function.Module.runMain (module.js:665:10)
    at startup (bootstrap_node.js:201:16)
    at bootstrap_node.js:626:3

Actual: Process exits with no error message and an exit code of 0.

• Version: 8.6.0
• Platform: Linux x64
• Subsystem: ESM

[evanlucas]

Interesting...on macOS, I see this:

v8.5.0

(node:1855) ExperimentalWarning: The ESM module loader is experimental.
Error: module /Users/evan/xxx.mjs not found
    at module.exports (internal/loader/search.js:16:12)
    at resolveRequestUrl (internal/loader/resolveRequestUrl.js:81:13)
    at Loader.import (internal/loader/Loader.js:61:27)
    at Function.Module._load (module.js:462:27)
    at Function.Module.runMain (module.js:665:10)
    at startup (bootstrap_node.js:201:16)
    at bootstrap_node.js:626:3

v8.6.0

(node:1920) ExperimentalWarning: The ESM module loader is experimental.
{ Error: ENOENT: no such file or directory, lstat '/null'
    at realpathSync (fs.js:1658:15)
    at resolveRequestUrl (internal/loader/resolveRequestUrl.js:88:18)
    at Loader.import (internal/loader/Loader.js:61:27)
    at Function.Module._load (module.js:462:27)
    at Function.Module.runMain (module.js:665:10)
    at startup (bootstrap_node.js:187:16)
    at bootstrap_node.js:607:3 errno: -2, code: 'ENOENT', syscall: 'lstat', path: '/null' }

So looks like something has definitely changed

[targos]

It's caused by dce72c2. I'm looking into it.