Two SPC tests fail on Chrome/Edge with flaky webdriver error

[stephenmcgruer]

From https://wpt.fyi/results/secure-payment-confirmation?label=experimental&label=master&aligned, both authentication-cross-origin.sub.https.html and enrollment-in-iframe.sub.https.html flaky-fail with an ERROR from webdriver:

ERROR message: target frame detached
  (Session info: chrome=102.0.4997.0)
Traceback (most recent call last):
  File "/home/test/web-platform-tests/tools/wptrunner/wptrunner/executors/executorwebdriver.py", line 403, in run_func
    self.result = True, self.func(self.protocol, self.url, self.timeout)
  File "/home/test/web-platform-tests/tools/wptrunner/wptrunner/executors/executorwebdriver.py", line 493, in do_testharness
    result = protocol.base.execute_script(
  File "/home/test/web-platform-tests/tools/wptrunner/wptrunner/executors/executorwebdriver.py", line 50, in execute_script
    return method(script)
  File "/home/test/web-platform-tests/tools/webdriver/webdriver/client.py", line 20, in inner
    return func(self, *args, **kwargs)
  File "/home/test/web-platform-tests/tools/webdriver/webdriver/client.py", line 791, in execute_async_script
    return self.send_session_command("POST", "execute/async", body)
  File "/home/test/web-platform-tests/tools/webdriver/webdriver/client.py", line 659, in send_session_command
    return self.send_command(method, url, body, timeout)
  File "/home/test/web-platform-tests/tools/webdriver/webdriver/client.py", line 623, in send_command
    raise err
webdriver.error.WebDriverException: target frame detached (404): target frame detached
  (Session info: chrome=102.0.4997.0)

Remote-end stacktrace:

#0 0x55e43b2a73e9 <unknown>
#1 0x55e43b2429a3 <unknown>
#2 0x55e43af55c17 <unknown>
#3 0x55e43af4212e <unknown>
#4 0x55e43af410a0 <unknown>
#5 0x55e43af4158b <unknown>
#6 0x55e43af414e5 <unknown>
#7 0x55e43af486c8 <unknown>
#8 0x55e43af48af6 <unknown>
#9 0x55e43af428bc <unknown>
#10 0x55e43af42fd4 <unknown>
#11 0x55e43af42d42 <unknown>
#12 0x55e43af4227c <unknown>
#13 0x55e43af410a0 <unknown>
#14 0x55e43af4158b <unknown>
#15 0x55e43af5fc90 <unknown>
#16 0x55e43af58663 <unknown>
#17 0x55e43af582ce <unknown>
#18 0x55e43af58aae <unknown>
#19 0x55e43af58db7 <unknown>
#20 0x55e43af59128 <unknown>
#21 0x55e43af5975b <unknown>
#22 0x55e43afbc3de <unknown>
#23 0x55e43afa8a92 <unknown>
#24 0x55e43afbb5dc <unknown>
#25 0x55e43afa8983 <unknown>
#26 0x55e43af7eddb <unknown>
#27 0x55e43af7ffb5 <unknown>
#28 0x55e43b270700 <unknown>
#29 0x55e43b2825da <unknown>
#30 0x55e43b28230c <unknown>
#31 0x55e43b282b12 <unknown>
#32 0x55e43b271b3c <unknown>
#33 0x55e43b282d7d <unknown>
#34 0x55e43b263c7d <unknown>
#35 0x55e43b299708 <unknown>
#36 0x55e43b299892 <unknown>
#37 0x55e43b2b39ee <unknown>
#38 0x7f5730f46609 <unknown>
#39 0x7f57309ec293 <unknown>

Initial investigation from @KyleJu implied that it started failing on April 8th - https://wpt.fyi/results/secure-payment-confirmation?q=authentication-cross-origin.sub.https.html&run_id=5633278756257792&run_id=5714671674851328

I'm able to reproduce locally on my MacOS device with a Chrome Dev run.

I tried looking for other tests failing this way, but have been unable to find any, so perhaps the tests are doing something unsupported? They both use a temporary cross-origin iframe to do credential enrollment, hosting https://{{hosts[alt][]}}:{{ports[https][0]}}/secure-payment-confirmation/resources/iframe-enroll.html (and are the only users of that file I believe).

[stephenmcgruer]

(Turns out to be user-error, #34559 has the fix)