Python classic buildpack build-time `PATH` change
Change effective on 09 December 2025
The Python classic buildpack, used by Cedar-generation apps, no longer adds the current working directory to the PATH environment variable used during the build. This prevents build errors if the app source code contains executable scripts or binaries that match the name of internal commands run by the buildpack.
If your Python app runs custom binaries or scripts from the root directory of your app during the build and you now see command not found errors when they are run, you will need to adjust the way you call those commands to include an explicit relative path prefix: ./
For example, if you have a script named my_script in the root of your app that you run during the build, you will now need to call it using ./my_script and not my_script.
This change only affects the value of PATH used at build time, since the PATH used at app run-time has never included the current working directory.