I once code-reviewed a serious bug-fix, in Python, causing leaking threads to crash a server. The bug turned out to be a bare try-except hiding a function call

I once code-reviewed a serious bug-fix, in Python, causing leaking threads to crash a server. The bug turned out to be a bare try-except hiding a function call with a missing argument; 2 args passed instead of 3. Not exactly a syntax error, but pretty close.