Claude Code watches for moments when it freezes up, called event-loop stalls (the event loop is the part of the program that handles work in turn). In interactive sessions, though not in print mode, this detector is now told to account for SIGCONT, the signal a program gets when it resumes after being suspended, for example after Ctrl+Z.
This sits behind tengu_drift_lantern. The flag server returned it as on for this site's account and for the anonymous baseline, in readings not taken under this release.
This is about the accuracy of stall measurements Claude Code collects. It changes the data rather than how Claude Code behaves for you. It appears meant to stop time spent suspended from being counted as a stall.
tengu_drift_lantern Off by default, switched on for this accountThe shipped code defaults this off, and the flag server returned on for the one account this site reads on this version. That is the reading that makes the entry above worth a second look, and it still says nothing about your account.
This account: on · anonymous baseline: on · compiled default in v2.1.288: off
These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.
Read once, for one account on one subscription tier, against v2.1.288. It isn't a statement about your account. What a flag value here can and cannot tell you
It is not confirmed what accounting for SIGCONT does inside the detector.