If you need support for the emitDecoratorMetadata typescript compiler option, import the emitDecoratorMetadata build extension and use it in your trigger.config.ts file: 
import { defineConfig } from "@trigger.dev/sdk/v3";
import { emitDecoratorMetadata } from "@trigger.dev/build/extensions/typescript";

export default defineConfig({
  project: "<project ref>",
  // Your other config settings...
  build: {
    extensions: [emitDecoratorMetadata()],
  },
});
This is usually required if you are using certain ORMs, like TypeORM, that require this option to be enabled. It’s not enabled by default because there is a performance cost to enabling it.
emitDecoratorMetadata works by hooking into the esbuild bundle process and using the TypeScript compiler API to compile files where we detect the use of decorators. This means you must have emitDecoratorMetadata enabled in your tsconfig.json file, as well as typescript installed in your devDependencies.