investigate flaky addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-hex

[Trott]

• Version: v10.0.0-pre
• Platform: alpine35-container-x64/
• Subsystem: test

https://ci.nodejs.org/job/node-test-commit-linux/15185/nodes=alpine35-container-x64/console

not ok 1910 addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-hex
  ---
  duration_ms: 7.576
  severity: crashed
  stack: |-
    oh no!
    exit code: CRASHED (Signal: 9)
  ...

[bnoordhuis]

Signal 9 = SIGSEGV. If you can obtain a backtrace and a disassembly of the call site + info registers, I can probably figure out what the issue is.

Educated guess: missing nullptr check somewhere.

[apapirovski]

Given that this seems to be happening solely on Linux-based containers — is it possible this has to do with memory overcommitting? Signal 9 is SIGKILL, afaik, which would signal that the malloc test succeeds (due to overcommitting) but then the memory is not actually available when it tries to actually use it later on in the test.

(SIGSEGV is 11, right?)

[Trott]

Might have a totally different cause then the Linux SIGSEGV (which I haven't seen in a while now), but it timed out on macOS today:

https://ci.nodejs.org/job/node-test-commit-osx/18382/nodes=osx1010/console

not ok 2007 addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-hex
  ---
  duration_ms: 120.392
  severity: fail
  exitcode: -15
  stack: |-
    timeout
  ...

Host was test-requireio-osx1010-x64-1. Tests seem to run a significantly faster on the macstadium hosts. This one typically takes 4 seconds or so on macstadium but can take 10 or 50 seconds on requireio. If we're moving off of requireio, then we can probably ignore this timeout until we see it on macstadium. (Are we moving to exclusively using macstadium, @nodejs/build?)

[apapirovski]

@nodejs/build Anyone want to investigate the memory overcommit suggestion and disable it on Alpine machines? It makes it impossible to detect available memory which tests like this one rely on.