In the Mohave we don't waste that kind of time <--- that's my best smartass response.

Making a dark gumbo roux typically takes 30 to 60 minutes of constant stirring on the stovetop, though it can require 2 to 2.5 hours if using the oven method.

Stovetop Method: Cooking over medium-low heat generally requires 30–45 minutes to reach a dark chocolate brown color. Some cooks prefer a slower process taking 45–75 minutes to develop deeper flavor without burning.
Oven Method: This approach requires significantly more time, approximately 2 to 2.5 hours, but only demands brief stirring intervals, making it less labor-intensive.
Key Factors: The exact time depends on the quantity of flour and fat, the type of fat used (e.g., oil vs. bacon drippings), and the heat level. Higher heat shortens the time but increases the risk of burning, which ruins the roux.
Visual Cue: The roux is ready when it reaches a deep chocolate brown color and emits a nutty aroma, with no black flecks visible.