warp: test failure: Run, chunked bodies, in chunks

[robx]

I caught a test failure building warp 3.2.23 on guix:

Failures:

  test/RunSpec.hs:300:17: 
  1) Run, chunked bodies, in chunks
       expected: ["Hello World\nBye","Hello World"]
        but got: []

  To rerun use: --match "/Run/chunked bodies/in chunks/"

Randomized with seed 596329956

Is this maybe the same problem as referenced in the comment above?

wai/warp/test/RunSpec.hs

Line 323 in 366f108

-- For some reason, the following test on Windows causes the socket

For the moment, this isn't reproducible, but I wanted to note it before it gets lost.

[robx]

By spinning that test, I get it to fail quite reliably, within a ~100 iterations / a couple of seconds.

Raising the threadDlay by a factor 10 it happens less frequently, but it still fails now and then (after 37s this time).

With threadDelay a 10th of the original, it fails directly.

[snoyberg]

Please test against the latest version on master, which enables -threaded in the test suite. See f612eb3

[robx]

I haven't managed to set up a master build on the guix vm yet, but applying the -threaded change by itself doesn't fix the issue.

(Do you know a way to verify that the test executable I built is compiled with -threaded? The build environment is a bit tricky to work with.)

[robx]

It does behave a bit differently now: Most of the time it fails after precisely 4 iterations, and with half the expected result instead of an empty result.

$ ./dist/build/spec/spec -m /Run/chunked\ bodies/in\ chunks/ 

Run
  chunked bodies
    in chunks FAILED [1]

Failures:

  test/RunSpec.hs:300:17: 
  1) Run, chunked bodies, in chunks
       expected: (4,["Hello World\nBye","Hello World"])
        but got: (4,["Hello World\nBye"])

When it doesn't fail right away, it always spins for a while, typically taking longer to fail than before the -threaded change. E.g.:

Run
  chunked bodies
    in chunks FAILED [1]

Failures:

  test/RunSpec.hs:300:17: 
  1) Run, chunked bodies, in chunks
       expected: (867,["Hello World\nBye","Hello World"])
        but got: (867,["Hello World\nBye"])

  To rerun use: --match "/Run/chunked bodies/in chunks/"

Of course, it's very much unclear these changes in behaviour aren't accidental.

[snoyberg]

You can use ./executable +RTS --info. On my system: the non-threaded runtime includes ,("RTS way", "rts_v"), and the threaded runtime includes ,("RTS way", "rts_thr").

[robx]

Thanks; then yes, I am using the threaded runtime.

[robx]

I've built version 3.2.27 now, and I can't get it to fail anymore, whether I pass -threaded or not. If it was fixed between 3.2.23 and 3.2.27 my apologies for the outdated report. Could also be chance of course. I'm letting it spin for a bit now.

[robx]

It seems stable, feel free to close.

[snoyberg]

Cool, thanks for confirming.