Alexander Aprelev

Again https://logs.chromium.org/logs/dart/buildbucket/cr-buildbucket/8704325355839192129/+/u/collect_shards/dartfuzz_-_generated_programs_shard_3/task_stdout_stderr:_dartfuzz_-_generated_programs_shard_3

@mraleph , @derekxu16 mentioned you wanted to keep block-based sample buffer that he wanted to remove to get rid of these crashes. Is it still the case?

I am not sure I would call `late final` variables mutable. They have to be written and initialized before they are used, but initialized only once.

ah, that aspect I believe is captured by existing https://github.com/dart-lang/sdk/issues/61962

> the variable has a sentinel value which passes the check. I was thinking that sentinel values should fail the "deeply-immutability" check.

failed again https://ci.chromium.org/ui/p/dart/builders/ci.sandbox/vm-tsan-linux-release-x64/1053/overview ``` ================== WARNING: ThreadSanitizer: data race (pid=292803) Write of size 8 at 0x5555591d12a0 by thread T7: #0 dart::TimelineStream::set_enabled(bool) out/ReleaseTSANX64/../../runtime/vm/timeline.h:118:45 (dartvm+0x28dfc53) (BuildId: 5ea745966addc539a4c7a97a42b3c3550049fdee) #1 dart::Timeline::Cleanup() out/ReleaseTSANX64/../../runtime/vm/timeline.cc:347:24 (dartvm+0x28dfc53) #2...

One issue seems to be that files in `perf` folder are actually Links on Windows, so they are filtered out by https://github.com/dart-lang/sdk/blob/49dc34715e4069e628b816185719fa006617f159/pkg/perf_witness/lib/src/common.dart#L30. Second issue seems to be that pid of...

Also it looks like .timeline files are not being flushed out in time, so their content remains blank when test inspects it.

thanks @scheglov , perhaps DATA_VERSION should be more eagerly incremented as current behavior results in significant amount of developer's time wasted(like chasing dart->flutter failed rolls).

https://dart-ci.appspot.com/log/vm-mac-debug-x64/vm-mac-debug-x64/3983/standalone/io/stdout_stderr_test another flake