Asynchronous sydTest hangs

[Mansindam]

Exception (reporting due to +RTS -xc): (THUNK_STATIC), stack trace:
GHC.Internal.IO.mask3,
called from Control.Concurrent.Async.Internal.catchAll,
called from Control.Concurrent.Async.Internal.concurrently',
called from Control.Concurrent.Async.Internal.concurrently,
called from Test.Syd.Runner.Asynchronous.runSpecForestInterleavedWithOutputAsynchronously,
called from GHC.Internal.Control.Exception.Base.bracket1,
called from GHC.Internal.System.Environment.withArgs2,
called from Test.Syd.Runner.withNullArgs,
called from Test.Syd.Runner.sydTestOnce,
called from Test.Syd.Runner.sydTestResult,
called from Test.Syd.sydTestWith,
called from Main.sydTest,
called from Main.tt,
called from Main.mainL,
called from Main.main,
called from GHC.Internal.TopHandler.runMainIO1

[Mansindam]

works fine synchronously: sydTestWith S.defaultSettings { S.settingThreads = S.Synchronous }

[NorfairKing]

Hi @Mansindam please show me the code :)

[Mansindam]

https://codeberg.org/JamesFaure/Irie/src/commit/8a8b3024b71fc1d194b4e7cb3ffaf3c9ef523b23/compiler/Main.hs#L498

[NorfairKing]

That's certainly strange.
I find your code a bit difficult to read.
Could you repro this problem with a minimal example?

[Mansindam]

I tried a little, it's very flaky and once seemed to depend on using or not a let-bound 'it'.
I reported this since he wasn't going to and thought you may make progress by simply auditing the threading code;
The backtrace indicates a race condition somewhere, unless something very weird is happening..

[NorfairKing]

@Mansindam could it be that you have a pure value that errors somewhere in the test definition?

[Mansindam]

That can happen under the SydTest.it, not outside of it.

[Mansindam]

I thought of trying S.settingThreads = (S.Asynchronous 1), result is the same static thunk

[Mansindam]

I went down the rabbit hole once again, this time this fails too (pretty sure that wasn't the case last time I tried)

tt = S.sydTest do
  S.it "l3" (pure "f = 3" >>= (`S.shouldBe` "3"))

Build profile: -w ghc-9.12.2 -O1

The first listed exception is copy-pasted a dozen times

*** Exception (reporting due to +RTS -xc): (THUNK_2_0), stack trace:
GHC.Internal.IO.throwIO,
called from GHC.Internal.IO.Exception.ioException,
called from GHC.Internal.IO.Exception.ioError1,
called from GHC.Internal.Stack.withFrozenCallStack,
called from GHC.Internal.Foreign.C.Error.throwErrno1,
called from GHC.Internal.Foreign.C.Error.throwErrnoIfMinus1Retry2,
called from GHC.Internal.Foreign.Marshal.Alloc.$wallocaBytesAligned,
called from GHC.Internal.IO.bracket1,
called from GHC.Internal.System.Posix.Internals.fileType4,
called from GHC.Internal.IO.FD.openFile4,
called from GHC.Internal.IO.Handle.FD.openBinaryFile2,
called from GHC.Internal.IO.Handle.FD.openBinaryFile5,
called from GHC.Internal.IO.Handle.FD.withBinaryFile1,
called from Autodocodec.Yaml.IO.readFirstYamlConfigFile,
called from Autodocodec.Yaml.IO.readYamlConfigFile,
called from GHC.Internal.Base.$fFunctorIO2,
called from GHC.Internal.Base.fmap,
called from GHC.Internal.Base.$fMonadIO1,
called from GHC.Internal.Base.>>=,
called from OptEnvConf.NonDet.runNonDetTLazy,
called from OptEnvConf.Run.runParserOn,
called from OptEnvConf.Run.runParser,
called from OptEnvConf.Run.runSettingsParser,
called from Test.Syd.OptParse.getSettings,
called from Test.Syd.sydTest,
called from Main.tt,
called from Main.mainL,
called from Main.main,
called from GHC.Internal.TopHandler.runMainIO1
WARNING: Only one CPU core detected, make sure to compile your test suite with these ghc options:
-threaded -rtsopts -with-rtsopts=-N
(This is important for correctness as well as speed, as a parallel test suite can find thread safety problems.)
*** Exception (reporting due to +RTS -xc): (THUNK_STATIC), stack trace:
GHC.Internal.IO.mask3,
called from Control.Concurrent.Async.Internal.catchAll,
called from Control.Concurrent.Async.Internal.concurrently',
called from Control.Concurrent.Async.Internal.concurrently,
called from Test.Syd.Runner.Asynchronous.runSpecForestInterleavedWithOutputAsynchronously,
called from GHC.Internal.Control.Exception.Base.bracket1,
called from GHC.Internal.System.Environment.withArgs2,
called from Test.Syd.Runner.withNullArgs,
called from Test.Syd.Runner.sydTestOnce,
called from Test.Syd.Runner.sydTestResult,
called from Test.Syd.sydTestWith,
called from Test.Syd.sydTest,
called from Main.tt,
called from Main.mainL,
called from Main.main,
called from GHC.Internal.TopHandler.runMainIO1

[NorfairKing]

This is suspicious:

called from Autodocodec.Yaml.IO.readFirstYamlConfigFile,
called from Autodocodec.Yaml.IO.readYamlConfigFile,
called from GHC.Internal.Base.$fFunctorIO2,
called from GHC.Internal.Base.fmap,
called from GHC.Internal.Base.$fMonadIO1,
called from GHC.Internal.Base.>>=,
called from OptEnvConf.NonDet.runNonDetTLazy,
called from OptEnvConf.Run.runParserOn,
called from OptEnvConf.Run.runParser,
called from OptEnvConf.Run.runSettingsParser,
called from Test.Syd.OptParse.getSettings,

It suggests that the issue occurs while reading your config file.

Also be sure to take note of the warning:

WARNING: Only one CPU core detected, make sure to compile your test suite with these ghc options:
-threaded -rtsopts -with-rtsopts=-N
(This is important for correctness as well as speed, as a parallel test suite can find thread safety problems.)

Edit: Are you perhaps running multiple sydTest invocations at the same time instead of running it once on multiple specs?

[Mansindam]

I'm running just one, on purpose with a single thread to reduce weirdness

Massive discovery: it works if i don't enable profiling
it also hangs at ghci

I test through ghci since that is orders of magnitudes faster.. maybe it's a ghc bug then :/

[NorfairKing]

@Mansindam I'm pretty sure that the async runner won't work without -threaded. Could you try running with -threaded -N1?

[Mansindam]

Results of -N1 are above, I've always compiled -threaded, except possibly at ghci, where it hangs nondescriptively