diff --git a/ModularBot_garage/src/env_report.nim b/ModularBot_garage/src/env_report.nim
index 8739332..eab2a85 100644
--- a/ModularBot_garage/src/env_report.nim
+++ b/ModularBot_garage/src/env_report.nim
@@ -311,6 +311,166 @@ proc printBuildIdentity() =
       discard
   echo "[env] build binary=", bin, " size=", size, " mtime=", mtime
 
+# ── Part 2: warnings about env mistakes ──────────────────────────────────────
+#
+# This is the point of the report. A typo must be LOUD, not a silent no-op.
+# Two mistakes are caught:
+#
+#   1. an unknown TR_*/GUN_* name (e.g. TR_TMHORIZON_NSTATE, missing S);
+#   2. a compile-time `{.intdefine.}`/`{.strdefine.}`/`{.booldefine.}` symbol
+#      exported as an env var (e.g. `TMH_NSTATES=2`), which is NEVER read at
+#      runtime and therefore does nothing.
+#
+# The known-name set is assembled from the modules' exported env-name
+# constants; the remaining inline reads are listed once here. The guard test
+# `common_libs/tests/test_env_report.nim` scans the tree for env reads and for
+# intdefine/strdefine/booldefine symbols and fails loudly if a name read
+# anywhere (or a new define) is missing from these tables, so neither can
+# silently drift.
+
+proc knownEnvNames*(): seq[string] =
+  ## Every TR_*/GUN_* name this project reads at runtime. Order is irrelevant;
+  ## callers put it in a set. Keep in sync with the tree scan in the guard test.
+  result = @[
+    # exported constants — the single source of truth (do not re-spell these)
+    MetricEnvVar, SelectorModeEnvVar, TieBreakEnvVar,
+    PowerPolicyEnvVar, PowerFarDistEnvVar, PowerFarCapEnvVar, PowerMidCapEnvVar,
+    PowerRefEnvVar, PowerEnergyHiEnvVar, PowerEnergyLoEnvVar,
+    PowerEnergyMinEnvVar, PowerEnergyMaxEnvVar, PowerFinishKillEnvVar,
+    PatternRadOffsetEnvVar, PatternRadScaleEnvVar,
+    TMH_SHIFT_ENV, TMH_BIG_MULT_ENV, TMH_LOG_ENV, TMH_RESET_ON_TARGET_ENV,
+    TMH_WINDOW_ENV, TMH_RESET_DROP_ENV, TMH_NSTATES_ENV, TMH_ACCURVE_ENV,
+    TMH_RETRAIN_EVERY_ENV, TMH_EPOCHS_ENV,
+  ]
+  # rack names are constructed from the prefix + gun table, not spelled out
+  for g in RackGunNames:
+    result.add RackEnvPrefix & g
+  # inline reads with no exported constant (the guard test scans for these)
+  for n in [
+    "GUN_SELECTOR_WINDOW", "GUN_SELECTOR_MINOBS", "GUN_SELECTOR_TIE",
+    "GUN_SELECTOR_FLOOR", "GUN_SELECTOR_POOL", "GUN_SELECTOR_RANK",
+    "GUN_SELECTOR_SHRINK", "GUN_SELECTOR_DWELL", "GUN_SELECTOR_MARGIN",
+    "GUN_SELECTOR_POINT_TIE", "GUN_SELECTOR_SEED",
+    "GUN_RACK_DISABLE", "GUN_STATS_PATH", "GUN_SHOTLOG_PATH",
+    "TR_MOVEMENT", "TR_MOVEMENT_LOG", "TR_RECORD_WORLDSTATE",
+    "TR_RADAR_FORCE_SPIN", "TR_RADAR_SCANLOG", "TR_RADAR_SCAN_LOG_PATH",
+    "TR_TRACKER_PROBE", "TR_TRACKER_PROBE_PATH", "TR_VBULLET_ADMIT_ONLY",
+    "TR_POWER_LOG",
+    "TR_RAM_OPPORTUNITY", "TR_RAM_OPP_DIST", "TR_RAM_OPP_MARGIN",
+    "TR_RAM_ABORT_DMG", "TR_RAM_PLAN", "TR_RAM_PLAN_DIST",
+    "TR_RAM_PLAN_MARGIN", "TR_RAM_PLAN_HITRATE", "TR_RAM_LOG",
+    "TR_TFIL_RANGE_LO", "TR_TFIL_RANGE_HI", "TR_TFIL_RANGE_TEMP",
+    "TR_TFIL_RANGE_K", "TR_TFIL_CORRIDOR_HEAT", "TR_TFIL_WALL_HOTNESS",
+    # harness vars (read by the test framework, inherited by the bot, so they
+    # must NOT be reported as typos)
+    "TR_SERVER_JAR", "TR_BATTLE_RUNNER", "TR_BATTLE_RUNNER_DIR",
+    # the report's own switch
+    EnvReportEnableEnvVar,
+  ]:
+    result.add n
+
+proc unknownEnvNames*(pairs: openArray[(string, string)]): seq[string] =
+  ## Pure: every TR_*/GUN_* name in `pairs` the bot does not read, sorted.
+  ## Anything else (e.g. PATH, JAVA_HOME) is deliberately ignored.
+  let known = knownEnvNames().toHashSet()
+  for (key, _) in pairs:
+    if (key.startsWith("TR_") or key.startsWith("GUN_")) and key notin known:
+      result.add key
+  result.sort()
+
+type
+  DefineMapping* = object
+    ## A `{.intdefine.}`/`{.strdefine.}`/`{.booldefine.}` symbol and the runtime
+    ## env var (if any) that actually controls the same knob. `suggestedEnv` is
+    ## the env name a user would naturally guess, used only for the
+    ## "does not exist" text when `runtimeEnv` is empty.
+    defineName*:   string
+    runtimeEnv*:   string
+    suggestedEnv*: string
+
+## Derived by grepping the tree for intdefine/strdefine/booldefine (see the
+## guard test, which re-greps and fails if this table drifts):
+##   tm_horizon.nim:101,102,103,106,108,139  — TMH_* ; only NSTATES has an env
+##   tm_pattern.nim:50,53,55,57,59,62,65,68,69,85,87,92,94,96 — TM_*
+##   tsetlin.nim:29,116,118,119,120          — TM_*
+## docs/env_reference.md documents the same table.
+const CompileTimeDefineMap*: seq[DefineMapping] = @[
+  # tm_horizon.nim — the ONLY define with a runtime twin (`TR_TMHORIZON_NSTATES`)
+  DefineMapping(defineName: "TMH_NSTATES", runtimeEnv: "TR_TMHORIZON_NSTATES"),
+  DefineMapping(defineName: "TMH_NCLAUSES", suggestedEnv: "TR_TMHORIZON_NCLAUSES"),
+  DefineMapping(defineName: "TMH_S_DEF", suggestedEnv: "TR_TMHORIZON_S_DEF"),
+  DefineMapping(defineName: "TMH_MIN_OBS", suggestedEnv: "TR_TMHORIZON_MIN_OBS"),
+  DefineMapping(defineName: "TMH_STALE_MAX", suggestedEnv: "TR_TMHORIZON_STALE_MAX"),
+  # tm_pattern.nim — no env form at all; do not invent a plausible one
+  DefineMapping(defineName: "TM_NCLAUSES"),
+  DefineMapping(defineName: "TM_NSTATES"),
+  DefineMapping(defineName: "TM_MIN_OBS"),
+  DefineMapping(defineName: "TM_CLASSES"),
+  DefineMapping(defineName: "TM_CONF_MARGIN_DEF"),
+  DefineMapping(defineName: "TM_SHRINK_DEF"),
+  DefineMapping(defineName: "TM_GF_MODE"),
+  DefineMapping(defineName: "TM_SOFT_BETA_DEF"),
+  DefineMapping(defineName: "TM_RADIAL_RANGE_DEF"),
+  DefineMapping(defineName: "TM_RAD_MARGIN_DEF"),
+  DefineMapping(defineName: "TM_REV_TURN_DEG_DEF"),
+  DefineMapping(defineName: "TM_REV_MARGIN_DEF"),
+  DefineMapping(defineName: "TM_REV_GAIN_DEF"),
+  # tsetlin.nim — no env form at all
+  DefineMapping(defineName: "TM_N_CLAUSES"),
+  DefineMapping(defineName: "TM_N_STATES"),
+  DefineMapping(defineName: "TM_T_DEF"),
+  DefineMapping(defineName: "TM_WINDOW_SIZE"),
+  # TM_S_DEF is shared by tm_pattern.nim AND tsetlin.nim (one -d sets both)
+  DefineMapping(defineName: "TM_S_DEF"),
+]
+
+proc isCompileTimeDefine*(name: string): bool =
+  ## True when `name` is one of our -d: symbols (never a runtime env var).
+  for m in CompileTimeDefineMap:
+    if m.defineName == name: return true
+
+proc setCompileTimeDefines*(pairs: openArray[(string, string)]): seq[string] =
+  ## Pure: the -d: symbols present as env vars, sorted.
+  for (key, _) in pairs:
+    if isCompileTimeDefine(key): result.add key
+  result.sort()
+
+proc defineWarningMessage*(defineName, value: string): string =
+  ## The exact warning text for one -d: symbol set as an env var. "" when the
+  ## name is not a known define.
+  for m in CompileTimeDefineMap:
+    if m.defineName != defineName: continue
+    let head = "[env] WARNING: " & defineName & "=" & value &
+               " is a COMPILE-TIME define (-d:" & defineName & "=" & value &
+               ") and is NOT read at runtime; "
+    if m.runtimeEnv.len > 0:
+      return head & "the runtime equivalent is " & m.runtimeEnv & "=" & value & "."
+    if m.suggestedEnv.len > 0:
+      return head & m.suggestedEnv &
+             " does not exist - this knob is compile-time only."
+    return head & "no runtime env equivalent exists - this knob is " &
+           "compile-time only."
+  return ""
+
+proc printMistakeWarnings*() =
+  ## The two warning paths, boot-only. Emits nothing when the env is clean, so
+  ## a correct run keeps the documented A/B/build shape.
+  var pairs: seq[(string, string)]
+  for key, val in envPairs():
+    pairs.add (key, val)
+
+  let unknown = unknownEnvNames(pairs)
+  let defines = setCompileTimeDefines(pairs)
+  if unknown.len == 0 and defines.len == 0: return
+
+  echo "[env] --- warnings: misnamed variables ---"
+  for key in unknown:
+    echo "[env] WARNING: ", key,
+         " is not a recognized TR_*/GUN_* variable; it is IGNORED. " &
+         "Check the spelling (see docs/env_reference.md)."
+  for key in defines:
+    echo defineWarningMessage(key, getEnv(key, ""))
+
 # ── the entry point ──────────────────────────────────────────────────────────
 
 var envReportDone = false
@@ -329,6 +489,7 @@ proc printEnvReport*(ctx: EnvReportContext) =
 
   echo "[env] === ENVIRONMENT (boot report) ==="
   printRawEnvironment()
+  printMistakeWarnings()
   printEffectiveValues(ctx)
   printBuildIdentity()
   echo "[env] === END ENVIRONMENT ==="
diff --git a/common_libs/tests/test_env_report.nim b/common_libs/tests/test_env_report.nim
new file mode 100644
index 0000000..4a12426
--- /dev/null
+++ b/common_libs/tests/test_env_report.nim
@@ -0,0 +1,161 @@
+## Guard test for the boot-time env report's Part 2 (the warnings).
+##
+## NO battle, NO Java, NO server. Run with:
+##   nim c -r common_libs/tests/test_env_report.nim
+##
+## It pins the two tables that must not drift:
+##   1. the KNOWN TR_*/GUN_* name set covers every env read in the tree, so a
+##      new knob cannot silently start producing a false "unknown variable"
+##      warning (and, conversely, the set cannot rot);
+##   2. the compile-time define map covers every `{.intdefine.}`/`{.strdefine.}`
+##      /`{.booldefine.}` symbol in the tree, and classifies the ONE real env
+##      twin (`TMH_NSTATES` -> `TR_TMHORIZON_NSTATES`) correctly.
+
+import std/[os, strutils, sets, sequtils]
+import gun_harness/selector
+import "../../ModularBot_garage/src/env_report"
+
+var failures = 0
+proc check(name: string, ok: bool) =
+  if ok: echo "PASS: ", name
+  else: echo "FAIL: ", name; inc failures
+
+const repoRoot = currentSourcePath().parentDir.parentDir.parentDir
+
+# ── the source surface the scan walks (the bot's real modules) ───────────────
+
+proc scannedFiles(): seq[string] =
+  ## .nim files under common_libs (excluding common_libs/tests, which are
+  ## probes/measurement scripts, not bot code) and ModularBot_garage/src.
+  ## env_report.nim is excluded: it DEFINES the known set, so scanning it is
+  ## circular (it also names "suggested but nonexistent" env vars on purpose).
+  for dir in [repoRoot / "common_libs", repoRoot / "ModularBot_garage" / "src"]:
+    for path in walkDirRec(dir):
+      if not path.endsWith(".nim"): continue
+      if "/tests/" in path: continue
+      if path.endsWith("/env_report.nim"): continue
+      result.add path
+
+proc literalsOn(line: string): seq[string] =
+  ## Double-quoted string literals on one line (env names have no escapes).
+  var i = 0
+  while i < line.len:
+    if line[i] == '"':
+      var j = i + 1
+      while j < line.len and line[j] != '"': inc j
+      if j >= line.len: break
+      result.add line[i + 1 ..< j]
+      i = j + 1
+    else:
+      inc i
+
+proc isKnownOrPrefix(name: string, known: HashSet[string]): bool =
+  ## A literal counts as covered when it is a known name OR a prefix of one
+  ## (`TR_RACK_` is the rack prefix; `TR_`/`GUN_` are the filter prefixes).
+  if name in known: return true
+  for k in known:
+    if k.startsWith(name): return true
+
+proc defineSymbolsOn(line: string): seq[string] =
+  ## `  TMH_NCLAUSES* {.intdefine.} = 40` -> "TMH_NCLAUSES"
+  for pragma in ["{.intdefine.}", "{.strdefine.}", "{.booldefine.}"]:
+    if pragma in line:
+      var sym = line.split('{')[0].strip()
+      if sym.endsWith("*"): sym.setLen(sym.len - 1)
+      let parts = sym.splitWhitespace()
+      if parts.len > 0: result.add parts[^1]
+
+# ── 1. the known-name set ────────────────────────────────────────────────────
+
+proc testKnownNames() =
+  let known = knownEnvNames()
+  let s = known.toHashSet()
+  check "known set has no duplicates", known.len == s.len
+  check "known set only holds TR_*/GUN_* names",
+        known.allIt(it.startsWith("TR_") or it.startsWith("GUN_"))
+  check "known set covers all 16 rack names",
+        RackGunNames.allIt((RackEnvPrefix & it) in s)
+  for name in ["TR_MOVEMENT", "TR_POWER_ENERGY_MIN", "TR_TMHORIZON_NSTATES",
+               "GUN_VBULLET_METRIC", "TR_ENV_REPORT", "GUN_SELECTOR_SEED",
+               "TR_RACK_TMHORIZON", "TR_TMHORIZON_NSTATES"]:
+    check "known set contains " & name, name in s
+
+# ── 2. the pure warning helpers ──────────────────────────────────────────────
+
+proc testUnknownEnvNames() =
+  let unknown = unknownEnvNames(@[
+    ("TR_POWER_LOG", "1"), ("GUN_STATS_PATH", "/tmp/x"),
+    ("TR_TMHORIZON_NSTATE", "5"), ("PATH", "/bin"),
+    ("TMH_NSTATES", "2"), ("JAVA_HOME", "/jdk")])
+  check "unknownEnvNames finds the misspelled TR_* only",
+        unknown == @["TR_TMHORIZON_NSTATE"]
+  check "unknownEnvNames ignores non TR_*/GUN_* names",
+        unknownEnvNames(@[("PATH", "/bin")]) == @[]
+
+proc testDefineMap() =
+  check "isCompileTimeDefine(TMH_NSTATES)", isCompileTimeDefine("TMH_NSTATES")
+  check "isCompileTimeDefine(TM_S_DEF)", isCompileTimeDefine("TM_S_DEF")
+  check "isCompileTimeDefine(TR_TMHORIZON_NSTATES) is false",
+        not isCompileTimeDefine("TR_TMHORIZON_NSTATES")
+  check "defineWarningMessage is empty for a non-define",
+        defineWarningMessage("TR_MOVEMENT", "x") == ""
+
+  let m1 = defineWarningMessage("TMH_NSTATES", "2")
+  check "TMH_NSTATES warns it is compile-time and names TR_TMHORIZON_NSTATES",
+        "COMPILE-TIME define (-d:TMH_NSTATES=2)" in m1 and
+        "TR_TMHORIZON_NSTATES=2" in m1
+  let m2 = defineWarningMessage("TMH_NCLAUSES", "40")
+  check "TMH_NCLAUSES says TR_TMHORIZON_NCLAUSES does not exist",
+        "TR_TMHORIZON_NCLAUSES does not exist" in m2
+  let m3 = defineWarningMessage("TM_S_DEF", "1.5")
+  check "TM_S_DEF says this knob is compile-time only",
+        "compile-time only" in m3
+
+  let defs = setCompileTimeDefines(@[
+    ("TMH_NSTATES", "2"), ("TR_MOVEMENT", "tfil"), ("TM_S_DEF", "1.5")])
+  check "setCompileTimeDefines finds both -d symbols",
+        defs == @["TMH_NSTATES", "TM_S_DEF"]
+
+# ── 3. the tree scans (the anti-drift guard) ─────────────────────────────────
+
+proc testTreeScan() =
+  let known = knownEnvNames().toHashSet()
+  var literals = 0
+  var missing: seq[string]
+  for path in scannedFiles():
+    for line in lines(path):
+      for lit in literalsOn(line):
+        if lit.startsWith("TR_") or lit.startsWith("GUN_"):
+          inc literals
+          if not isKnownOrPrefix(lit, known):
+            missing.add path.extractFilename & ":" & lit
+  check "tree scan is alive (>= 50 TR_*/GUN_* literals)", literals >= 50
+  check "every TR_*/GUN_* literal in the tree is in the known set: " &
+        $missing, missing.len == 0
+
+proc testDefineScan() =
+  let mapped = CompileTimeDefineMap.mapIt(it.defineName).toHashSet()
+  var found: seq[string]
+  for path in scannedFiles():
+    for line in lines(path):
+      for sym in defineSymbolsOn(line):
+        found.add sym
+  var missing: seq[string]
+  for sym in found:
+    if sym notin mapped: missing.add sym
+  check "tree define scan is alive (>= 20 symbols)", found.len >= 20
+  check "every intdefine/strdefine/booldefine is in the map: " &
+        $missing, missing.len == 0
+
+# ── driver ───────────────────────────────────────────────────────────────────
+
+testKnownNames()
+testUnknownEnvNames()
+testDefineMap()
+testTreeScan()
+testDefineScan()
+
+if failures > 0:
+  echo "\n", failures, " check(s) FAILED"
+  quit(1)
+echo "\nAll env-report checks passed."