YAMLException unacceptable kind of an object to dump [object Undefined]

[adymorz]

Tests are running using gulp (5.0.0), ava (6.1.3) and execa (9.1.0). I recently updated those packages, but the error also occurred before, so the error is not directly related to those specific versions.

The code to run the test looks like this:

await execa("npx", [
	"ava",
	"tests/*,
	"--concurrency",
	parseInt(argv["ava-concurrency"]),
	argv["ava-failfast"] === true ? "--fail-fast" : null,
	"--tap",
	"--timeout",
	"30m"
], {
	env: {
		AVA_BROWSER: argv["ava-browser"],
		AVA_HEADLESS: argv["ava-headless"],
		AVA_PRESERVE_DB: argv["ava-preserve-db"],
		AVA_SKIP_SCREENSHOTS: argv["ava-skip-screenshots"],
	},
	stdout: [
		process.stdout,
		{file: "tests/output/tapOutput.txt"}
	]
});

Sporadically the following error gets thrown:

Command failed with exit code 1: npx ava tests/* --concurrency 4  --tap --timeout 5m

C:\Users\some-path\node_modules\js-yaml\lib\js-yaml\dumper.js:779
      throw new YAMLException('unacceptable kind of an object to dump ' + type);
            ^
YAMLException: unacceptable kind of an object to dump [object Undefined]
    at writeNode (C:\Users\some-path\node_modules\js-yaml\lib\js-yaml\dumper.js:779:13)
    at writeBlockMapping (C:\Users\some-path\node_modules\js-yaml\lib\js-yaml\dumper.js:657:10)
    at writeNode (C:\Users\some-path\node_modules\js-yaml\lib\js-yaml\dumper.js:750:9)
    at dump (C:\Users\some-path\node_modules\js-yaml\lib\js-yaml\dumper.js:840:7)
    at Object.safeDump (C:\Users\some-path\node_modules\js-yaml\lib\js-yaml\dumper.js:846:10)
    at Module.test (file:///C:/Users/some-path/node_modules/ava/node_modules/supertap/dist/index.js:46:49)
    at TapReporter.writeTest (file:///C:/Users/some-path/node_modules/ava/lib/reporters/tap.js:99:36)
    at TapReporter.consumeStateChange (file:///C:/Users/some-path/node_modules/ava/lib/reporters/tap.js:203:10)
    at file:///C:/Users/some-path/node_modules/ava/lib/reporters/tap.js:68:45
    at file:///C:/Users/some-path/node_modules/emittery/index.js:365:13 {
  reason: 'unacceptable kind of an object to dump [object Undefined]',
  mark: undefined
}

Node.js v20.10.0

Do you have an idea how to find the root cause of this issue?

[novemberborn]

Do you have an idea how to find the root cause of this issue?

Edit the installed reporter code and log the value being dumped. There's line numbers in the stack trace you posted.