E2BCodeExecutionException
e2b.exceptions.E2BCodeExecutionException
Stack trace
Traceback (most recent call last):
File "main.py", line 42, in <module>
result = e2b.execute(user_code) # triggers E2BCodeExecutionException
File "/usr/local/lib/python3.9/site-packages/e2b/executor.py", line 88, in execute
raise E2BCodeExecutionException(f"Execution failed: {err}")
e2b.exceptions.E2BCodeExecutionException: Execution failed: NameError: name 'undeclared_var' is not defined Why it happens
This error happens because the e2b environment attempts to run code that contains runtime errors such as undefined variables, syntax errors, or disallowed operations. The e2b executor catches these exceptions and raises E2BCodeExecutionException to signal failure.
Detection
Monitor e2b execution calls for exceptions of type E2BCodeExecutionException and log the raw user code and error message to identify the root cause before the application crashes.
Causes & fixes
User code references variables or functions that are not defined or imported
Ensure all variables and functions used in the code are properly declared or imported before execution.
User code contains syntax errors or invalid Python constructs
Validate and lint user code before execution to catch syntax errors and reject invalid code submissions.
User code attempts disallowed operations or restricted system calls blocked by e2b sandbox
Review and restrict user code to safe operations; update sandbox policies to allow necessary safe calls or reject unsafe code.
Code: broken vs fixed
import e2b
user_code = "print(undeclared_var)"
result = e2b.execute(user_code) # triggers E2BCodeExecutionException due to NameError
print(result)import os
import e2b
os.environ['E2B_API_KEY'] = os.environ['E2B_API_KEY'] # Use env var for auth
user_code = "declared_var = 42\nprint(declared_var)"
result = e2b.execute(user_code) # fixed: no undefined variables
print(result) # prints 42Workaround
Wrap e2b.execute() calls in try/except E2BCodeExecutionException, log the error and user code, then notify users to correct their code.
Prevention
Implement pre-execution code validation and sandboxing with strict static analysis to catch errors before runtime and ensure safe execution.