diff --git a/compiler/ccgtypes.nim b/compiler/ccgtypes.nim
index 095803e271..2fc37f6562 100644
--- a/compiler/ccgtypes.nim
+++ b/compiler/ccgtypes.nim
@@ -108,7 +108,14 @@ proc fillBackendName(m: BModule; s: PSym) =
     var result: Rope
     if s.kind in routineKinds and {optCDebug, optItaniumMangle} * m.g.config.globalOptions == {optCDebug, optItaniumMangle} and
       m.g.config.symbolFiles == disabledSf:
-      result = mangleProc(m, s, false).rope
+      # Under the per-module IC backend the bare-name uniqueness probe
+      # (`m.g.mangledPrcs`) only sees the routines of the CURRENT module, so the
+      # clean-vs-`makeUnique` decision is made independently per process: a
+      # method base mangles clean at its owner but loses the in-module race to
+      # its same-signature dispatcher elsewhere (clean `speak` defined twice ->
+      # "multiple definition"; demanders call `speak_u<n>` that nobody defines).
+      # Force the stable, disamb-based unique name so every process agrees.
+      result = mangleProc(m, s, makeUnique = m.config.cmd == cmdNifC).rope
     else:
       let shared = sharedInstanceCName(m, s)
       if shared.len > 0:
diff --git a/compiler/ccgutils.nim b/compiler/ccgutils.nim
index 5d16881604..9960ea807b 100644
--- a/compiler/ccgutils.nim
+++ b/compiler/ccgutils.nim
@@ -114,8 +114,19 @@ proc makeUnique(m: BModule; s: PSym, name: string = ""): string =
   result = if name == "": s.name.s else: name
   # keep backend-minted ids out of the `_u` namespace; their item counter
   # restarts at 0 and would collide with loaded symbols' ids
-  result.add(if s.itemId.isBackendMinted: "_c" else: "_u")
-  result.add $s.itemId.item
+  if s.itemId.isBackendMinted:
+    result.add "_c"
+    result.add $s.itemId.item
+  else:
+    result.add "_u"
+    # Mirror `mangleProcNameExt`: use the per-(module,name) `disamb`, NOT
+    # `itemId.item`. Under the per-module IC backend the same symbol is loaded
+    # from a NIF in many processes and `itemId.item` is a fresh, load-order
+    # dependent counter — so a method base would mangle to `_u1` in one module,
+    # `_u3` in another and clean at its owner, none of which link. `disamb` is
+    # assigned deterministically per (module, name) and is serialized, so every
+    # process that touches the symbol derives the identical C name.
+    result.add $s.disamb
   # module suffix LAST (a strippable trailing token; see `mangleProcNameExt`)
   result.add "__"
   result.add m.g.graph.ifaces[s.itemId.module].uniqueName
diff --git a/compiler/deps.nim b/compiler/deps.nim
index 4ab7617d0f..fb77792c3d 100644
--- a/compiler/deps.nim
+++ b/compiler/deps.nim
@@ -701,6 +701,14 @@ proc computeForwardedArgs(c: DepContext): seq[string] =
   # buckets (and rejects calls as ambiguous that multi-dispatch accepts)
   if optMultiMethods in c.config.globalOptions:
     result.add "--multimethods:on"
+  # Forward the debug-info switch: the cg children — not the driver — fill the
+  # backend C names, and `--debugger:native` selects the Itanium mangling
+  # scheme (ccgtypes.fillBackendName). A child without it would name routines
+  # with the plain `_u<disamb>` scheme while a sibling that read the project's
+  # config.nims (`--debugger:native`) used Itanium, so the same symbol's
+  # definition and cross-module references would disagree at link.
+  if optCDebug in c.config.globalOptions:
+    result.add "--debugger:native"
   # the children compile each MODULE as their own project file, which makes
   # that module's package the "main package" and unfilters foreign-package
   # diagnostics — a vendored package's hintAsError/warningAsError promotions
diff --git a/compiler/sempass2.nim b/compiler/sempass2.nim
index e1b37b21c6..f72548cf72 100644
--- a/compiler/sempass2.nim
+++ b/compiler/sempass2.nim
@@ -1126,7 +1126,15 @@ proc trackCall(tracked: PEffects; n: PNode) =
   # otherwise feed the magic to codegen. Mirrors the `tfTriggersCompileTime ->
   # sfCompileTime` path in `semProcAux`.
   if a.kind == nkSym and a.sym.magic in {mNLen..mNError, mSlurp..mQuoteAst} and
-      tracked.owner != nil and tracked.owner.kind in routineKinds:
+      tracked.owner != nil and tracked.owner.kind in routineKinds and
+      tracked.config.cmd != cmdNimscript:
+    # ...but NOT under `nim e`: nimscript has no codegen backend to protect, and
+    # marking a routine `sfCompileTime` makes `semExpr` eagerly fold calls to it
+    # at sem time (emConst), where module-level globals it reads have no VM slot
+    # yet — distros' `detectOsWithAllCmd` reaches `gorge` and reads the plain
+    # global `unameRes` → "cannot evaluate at compile time: unameRes". In the
+    # normal nimscript run (emRepl) the module's var section runs first and the
+    # slot exists, so the marking is both unnecessary and harmful here.
     incl(tracked.owner, sfCompileTime)
   if n.typ != nil:
     if tracked.owner.kind != skMacro and n.typ.skipTypes(abstractVar).kind != tyOpenArray: