"OSError: [Errno 8] Exec format error" when trying to run an executable in Flask

Hello everyone, I am deployed a Python Flask application to that utilizes the scoutfish executable for parsing PGN (Portable Game Notation) data. The application runs without issues locally, but upon deployment to Render, I encounter an error message “OSError: [Errno 8] Exec format error” when my script attempts to run the scoutfish executable.

Additional info:

  • My flask application is a simple server with only one route (/) that interacts with scoutfish.
  • I included the scoutfish executable files when deploying to Render.
  • My Python script uses PopenSpawn('./scoutfish', encoding='utf-8') to call the executable.
  • Scoutfish is written in C++

I would appreciate any help with this issue. Could you please advise on the proper way to ensure the scoutfish executable is accessible and executable within the Render environment for my Python application?

Hi there,

What OS what the scoutfish executable built for? Locally are you using Windows or MacOS? On Render, your service is running on Linux, so you will need to make sure this executable works on Linux.

Regards,

Keith
Render Support, UTC+10 :australia:

Hello Keith, Thanks for replying.

Yea that makes a lot of sense. I’m on a mac so it’s not compatible. Do you happen to know how I can make sure that my dev environment simulates production as much as possible to avoid these kind of problems in the future? Any resources or articles or anything else that can point me in the right direction? Thank you very much

Edit:
For more context, I plan to build applications using Node express. This was just a proof of concept using Flask

Hi there,

Personally, I just use my Mac, but I’m not pushing prebuilt binaries because I know this will cause issues. I’m not sure where you got the scoutfish binary from but if you could download a Linux/Ubuntu compatible binary or build it as part of your Render build, that should work.

If you want to have an environment more similar to the Renders Native environment, you could look into running an Unbuntu VM locally or setting up an Ubuntu Docker environment. There should be guides for doing this on the Internet. You could also choose to just use a Docker deploy option on Render, and then you can run the same image locally as you do on Render.

Regards,

Keith
Render Support, UTC+10 :australia: