ENGINE_PIN

f3adbb1315b26129f5e317af5279decefb1cea8f engine-v1
# THE INSTRUMENT. First field is the commit and it is the authority; second is the tag, and it is
# only a label. A tag can be force-moved, a content hash cannot, so the run verifies the tag still
# resolves here and refuses if it does not - the same rule gateways/*/build.sh applies to gateway
# pins, for the same reason: a moving ref makes two runs weeks apart incomparable while reporting
# the same string. Every row on the board is measured by this engine, and a board whose rows were
# measured by different engines is not a comparison - it is two experiments printed in one table.
#
# This file exists so that fact does not depend on anyone remembering a sha. run-on-ec2.sh reads it
# as the default BENCH_ENGINE_COMMIT, so the normal case - a new gateway version, a config change, a
# re-measure of one lagging row - is pinned to the frozen engine without anyone passing anything.
#
# WHAT DOES NOT REQUIRE CHANGING THIS FILE, which is nearly everything:
#   a gateway's pinned version, its config templates, its capability declaration, a new gateway, the
#   site, the auditors, this script. None of them are the instrument. Re-measure the affected rows
#   against this pin and the board stays one instrument, because it is one instrument.
#
# WHAT REQUIRES CHANGING IT: a genuine fix to engine/ or mock/ - the measurement itself. That is a
# board-wide event and costs a full fourteen-gateway re-run, because a number measured by the old
# engine and a number measured by the new one cannot share a table. Do not change this line to make
# a run go green. run-on-ec2.sh refuses to launch when the tree's engine/ and mock/ differ from this
# commit's, and that refusal is the feature: it is the difference between a frozen instrument and a
# remembered intention.
#
# Changing it means: rebuild the rig release from the new commit (bench-rig.yml, push to main
# touching engine/** or mock/**), update this file, re-run all fourteen.