A build module runs in the directory its build was unpacked in. When the
node-engine replaced that build, every command the module started inherited a
deleted working directory, and the toolchain probe's failure became a final
refusal of the check that asked it (three checks on ace on 2026-10-26).
forgekey: ExecRunnerClean starts its command in the HOME it is given, or the
temporary directory; the other runners keep the process's directory while it
exists and use the temporary directory once it is gone.
buildstep: a guard whose probe failed answers a Refusal with Again set; the
puller declines such an ask (delivery.StepDeclined) so its asker puts it again
for another node or a later pull, instead of ending it refused. A version
mismatch stays a refusal.
jschoubben
36061b5c56