Constant KTSTR_SCHEDULER_ENV 

pub const KTSTR_SCHEDULER_ENV: &str = "KTSTR_SCHEDULER";

Name of the environment variable that overrides the scheduler binary path test_support::eval uses for in-process scheduler dispatch. Read at crate::test_support::eval. This is the COARSE (global) override: it applies to EVERY SchedulerSpec::Discover scheduler regardless of name, so a test declaring multiple distinct schedulers can’t point them at different binaries through it — use the per-name variant (per_name_scheduler_env) for that.

Resolution precedence: the per-name override is checked FIRST; this global var is the fallback when no per-name var is set; if neither resolves, the cascade falls through to the workspace build.