I was debugging a Heisenbug once, developing embedded FW for a mobile phone.
After some time, I noticed that the phone seemingly only crashed in one area of the open office floorplan where I was working.
I started walking around the office testing this theory, not really believing it. But after a while, I had hard evidence that the bug would only manifest once I entered that part of the office.
When I came to terms that I wasn’t hallucinating, I realised what the problem was. There was poor reception in that part of the office, causing the phone’s modem to switch from 4G wideband to narrowband (glossing over details here), which triggered the bug.
Easy to see with hindsight, but I was very confused there and then
After some time, I noticed that the phone seemingly only crashed in one area of the open office floorplan where I was working.
I started walking around the office testing this theory, not really believing it. But after a while, I had hard evidence that the bug would only manifest once I entered that part of the office.
When I came to terms that I wasn’t hallucinating, I realised what the problem was. There was poor reception in that part of the office, causing the phone’s modem to switch from 4G wideband to narrowband (glossing over details here), which triggered the bug.
Easy to see with hindsight, but I was very confused there and then