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Incredibly fast JavaScript runtime, bundler, test runner, and package manager – all in one
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`Bun.spawnSync` works as expected the first time, but doesn't the next one. #7443

Open rempas opened 7 months ago

rempas commented 7 months ago

What version of Bun is running?

1.0.15+b3bdf22eb

What platform is your computer?

Linux 6.6.2-arch1-1 x86_64 unknown

What steps can reproduce the bug?

I am trying to use Bun.SpawnSync to run c compilers (gcc and clang for now) for a number of files. The idea is to create an alternative benchmark suite for Mir. I have limited the benchmarks to only two for now. The first one is compiled correctly, and the file is created. The second one is not. While the command is run correctly (no "catch"), I look at my directory and the file is not there.

The script is meant to run from the root directory! There are messages (console.log and console.error) that will help you understand what's going on in more detail.

What is the expected behavior?

To "spawn" the c compilers and create the output files. The first one is created. The second isn't.

What do you see instead?

What I do NOT see is the real question! I do not see the file I expect to see...

Additional information

I don't know. Ask me whatever you need! I'll be glad to help :)

Electroid commented 7 months ago

Thanks for reporting, though it's hard to get to the root of the issue you're describing. Are you seeing that spawnSync works the first time, then not the second? (what happens the 2nd time, does it throw an error, does not just show no output? does it work a third/fourth time?)

rempas commented 7 months ago

Thanks for reporting, though it's hard to get to the root of the issue you're describing. Are you seeing that spawnSync works the first time, then not the second? (what happens the 2nd time, does it throw an error, does not just show no output? does it work a third/fourth time?)

So, here is what's going on! First, I am using spawnSync to check if a bunch of compilers are installed in the system (look at the default_compilers variable). If a check fails, I know that the compiler doesn't exist. In that part, it seems to be working correctly, as it finds "gcc" and "clang" and it doesn't find anything else.

After that, I go to the actual compilation. There is a list of benchmarks (look at the benchmarks variable) that I run for each compiler that was found ("gcc" and "clang" in my case). For testing purposes, I have only kept 2 benchmarks. With that in mind, the compile_test function will run 8 times to check the compilers and then, 2 (number of benchmarks) times 2 (number of compilers), a total of 4 times for the actual compilation of the benchmarks! After the compilation is done, we try to execute these files from another function (run_test). Every benchmark is compiled and then run. Then we go to the next one, until we are done.

The first benchmark is a file called "array.c" so, we should have an output called "array.gcc" when GCC compiles it and "array.clang" when clang compiles it. This works correctly! The second one is a file called "binary-trees.c" so, GCC creates "binary-trees.gcc" and clang creates "binary-trees.clang". This doesn't happen, however! Unless I mess something in the loop, and it runs the first benchmark again, there must be a problem with spawnSync. This doesn't seem to be the problem however, as you will see, there is a console.log that prints the output that is about to be created! In the first benchmark, everything is ok but in the second time, spawnSync still executes without problems but when I used existsSync (from "node:fs"), the output files are not there!