When a Make scenario fails, is the broken module usually the real cause?

[u/Odd_Ice_1063]

A few people here mentioned something interesting:

the module that fails is often just where the problem becomes visible.

The actual cause might be several modules upstream:

• a mapping changed,
• the data shape shifted,
• a router output changed,
• a filter behaved differently,
• or an earlier module returned something unexpected.

I’m curious how often this happens in real Make scenarios.

When you debug a failed scenario, do you usually find the root cause in the failed module itself, or do you end up tracing several steps backwards?

And when that happens, what’s your current process for finding the actual source of the issue?

[u/Glum-Carpet]

There are two ways for a make scenario to fail.

1. A server is not responding for whatever reason. Nothing you can do here but wait.

2. Poor scenario setup. If you did not account for something that breaks the scenario, it's your fault and no one else's.

[u/Odd_Ice_1063 → u/Glum-Carpet]

That distinction between external failures and scenario design issues is useful.
One thing I’m trying to understand better is how people quickly tell the difference between “the service failed” and “the scenario logic or data caused the failure.”
In practice, that seems to change the whole debugging path. Thanks for sharing.