Project context:

• Framework: Flask (Python 3.11)

• Structure: Flask backend + templates + static files

• Dockerfile based on python:3.11-slim

• Database: SQLite

• Repository: hosted on GitHub and connected to Railway

Dockerfile (main part): FROM python:3.11-slim

WORKDIR /app

RUN apt-get update && apt-get install -y --no-install-recommends \

libsqlite3-dev sqlite3 build-essential \

&& rm -rf /var/lib/apt/lists/*

COPY requirements.txt .

RUN pip install --upgrade pip && pip install --no-cache-dir -r requirements.txt

COPY . .

CMD ["python", "app.py"]

Error message (always appears):
[paste here the exact error log from Railway]

What we already tried:

• Updated and verified requirements.txt

• Checked for a proper Procfile / startup command

• Tested the Dockerfile locally — the app runs fine on our machine

Could you please help us identify what might be causing this error in Railway’s environment?

Thank you very much!