So do we -- and it's how I noticed this. We have a "debug" build that compiles everything and runs unit tests, which runs on every commit on every branch (we u

So do we -- and it's how I noticed this. We have a "debug" build that compiles everything and runs unit tests, which runs on every commit on every branch (we use gitflow, so all actual work happens in feature branches). There's also a nightly (or manually triggered) "release" build that runs on the master and any release/* branches (if there are changes), and additionally does some i18n stuff (which includes the convoluted step of compiling a VB.NET app and then decompiling it into C# so we can run gettext on it), builds installers and does some other packaging tasks. The problem is this bug was dependent on when the tests ran. Commit on November 30th, and the debug build would be fine, but release build would fail the next night (Dec 1). Commit on October 30th, both will be fine as the release build runs on October 31st. November 1st is a Sunday so chances are no one was working on Saturday, which means no build, which means this failure isn't visible.