Local Success Has Been Submitted as Evidence

The code works.

This has been confirmed by the developer who wrote it, using the machine they wrote it on, in the environment they have been building for three years. The confirmation is accurate. On that machine, in that environment, the code produces the expected output.

The staging environment disagrees.

The Counterfactual

In a version of events where the code was written in an environment identical to staging, the code would also work in staging. The local environment and the staging environment would share dependencies, versions, and configuration, and behavior would be consistent across both.

This version of events did not occur. The local environment has:

• A node version that is two major versions behind the build pipeline.
• A package that was installed globally three years ago for an unrelated project.
• An environment variable set in a config file that was added during a week of debugging in 2024 and never committed.
• Three packages at versions that were pinned after they broke something, and which have not been updated since.

The Evidence

The local environment is the only environment where the code has been tested. It is also the environment the developer is most confident about, because they built it, they understand it, and it produces good results.

The staging environment is less familiar. It is configured by a process rather than by a person. It does not have the workarounds. It has the dependencies the project actually specifies.

The code works locally. The local environment is being submitted as character testimony on behalf of the code. The staging environment is asking clarifying questions.

The Resolution

The missing environment variable was identified. The global package had to be added to the project dependencies. The node version discrepancy required a .nvmrc file. The pinned packages had not been the issue but were updated in the process.

The code works in staging. It also still works locally. The environments are now more similar than they were, but not identical. The developer has a list of things that are different. The list will grow over time.

Next time the code is tested locally, it will work. Next time it is deployed, there will be something.