Add node --version to the start of your render-build.sh script;
In an effort to reduce image sizes, Node is available as a stub on non-Node services, the first time it is invoked it is loaded in. However, this includes the output we add about the version of it (and Bun) being used. You can see in the “JSON::ParserError” bit that there is version information with a trailing ["ok"]. ["ok"] is supposed to be the only thing printed, but the rest of our output causes the entire chunk of output to be invalid JSON.
Thus, you need to fully load Node in before it is needed to be used (by execjs I assume?).