Inconsistent bundling behavior between local machine and Docker container

[erik-balfe]

What version of Bun is running?

1.1.30

What platform is your computer?

Ubuntu 20.4 and docker image "oven/bun:1.1.30"

What steps can reproduce the bug?

1. Set up a project using llamaindex and other dependencies (full package.json available if needed, but currently llamaindex is enough for reproducing the error).
2. Create a build script (build.ts) that uses bun build with the following options:

     bun build MAIN_FILE --compile --minify --sourcemap --target bun --format esm --outfile OUTPUT_FILE

3. Build the project locally using bun run build.
4. Create a Dockerfile:

     FROM oven/bun:1.1.30
     WORKDIR /app
     COPY package.json bun.lockb* ./
     RUN bun install --frozen-lockfile
     COPY src/ ./src/
     COPY tsconfig.json ./
     COPY build.ts ./
     CMD ["bun", "run", "build"]

5. Build the Docker image and run it to produce the executable.
6. Compare the two executables (size, hash, and functionality).

What is the expected behavior?

The Docker-built executable should have the same size and functionality as the locally-built executable.

What do you see instead?

• The Docker build process completes successfully without errors.
• The Docker-built executable is smaller in size compared to the locally-built one.
• When running the Docker-built executable, an error occurs:

  error: Missing tiktoken_bg.wasm
   at node_modules/tiktoken/tiktoken.cjs:34:26

Additional information

• This issue persists with both the oven/bun:1.1.30 image and a custom Ubuntu-based image with Bun 1.1.30 installed.
• All dependencies are installed using the provided bun.lockb, ensuring consistency between local and Docker environments.
• Attempts to explicitly copy the tiktoken_bg.wasm file in the build process did not resolve the issue.
• The Docker environment has been verified to have the same dependencies, environment variables, and file structure as the local environment
• Various build options have been tried and different output formats (cjs, esm). All that i found in docs for --compile.
• The build script performs additional checks like ensuring correct Bun version and logging build environment details.
• The issue seems to be specific to how Bun handles certain dependencies (like tiktoken) during the bundling process in different environments.
• I also tried to specify the missing dependency as direct dependency in my package.json. It didnt help.

tsconfig in the project (if it makes sense)

{
  "compilerOptions": {
    "target": "ESNext",
    "module": "ESNext",
    "moduleResolution": "bundler",
    "esModuleInterop": true,
    "skipLibCheck": true,
    "noEmit": true,
    "allowJs": true,
    "ignoreDeprecations": "5.0",
    "isolatedModules": true,
    "resolveJsonModule": true,
    "forceConsistentCasingInFileNames": true,
    "strict": false,
    "strictNullChecks": true,
    "allowSyntheticDefaultImports": true
  },
  "include": ["src/**/*"],
  "exclude": ["node_modules"]
}

Questions:

1. Why is the bundler producing different outputs in these two environments despite using the same Bun version and lock file?
2. Is there a known issue with how Bun handles WebAssembly files (like tiktoken_bg.wasm) during the bundling process in containerized environments?
3. Are there any additional flags or configurations that should be used to ensure consistent bundling behavior across different environments?

Id be happy to provide any additional info about the bug if needed.

[erik-balfe]

I believe this issue is specifically related to wasm dependencies, as I have only encountered it with wasm packages in the error messages, and not with any others.

I face this problem on one of my machines very rarely when launching the same binary built with Bun. Most of the time, it works well. However, in all other environments (GitHub Actions, Docker, and other Linux machines), it occurs every time, despite using the exact same binary everywhere.