template with overload redefines proc

[Graveflo]

Nim Version

Nim Compiler Version 2.3.1 [Linux: amd64]
Compiled at 2025-11-15
Copyright (c) 2006-2025 by Andreas Rumpf

git hash: 79ddb7d
active boot switches: -d:release

Description

proc temp(one: int, two: int, three: int)  =
  discard

template temp(body: untyped): untyped =
  body

temp:
  proc a(tp: int) =
    discard

Current Output

/home/ryan/dev/nim/nimscraps/src/nimscraps.nim(35, 1) template/generic instantiation of `temp` from here
/home/ryan/dev/nim/nimscraps/src/nimscraps.nim(36, 3) Error: redefinition of 'a'; previous declaration here: /home/ryan/dev/nim/nimscraps/src/nimscraps.nim(36, 8)
Traceback (most recent call last)
/home/ryan/dev/nim/clones/Nim/compiler/nim.nim(169) nim
/home/ryan/dev/nim/clones/Nim/compiler/nim.nim(124) handleCmdLine
/home/ryan/dev/nim/clones/Nim/compiler/main.nim(324) mainCommand
/home/ryan/dev/nim/clones/Nim/compiler/main.nim(290) compileToBackend
/home/ryan/dev/nim/clones/Nim/compiler/main.nim(153) commandCompileToC
/home/ryan/dev/nim/clones/Nim/compiler/pipelines.nim(341) compilePipelineProject
/home/ryan/dev/nim/clones/Nim/compiler/pipelines.nim(260) compilePipelineModule
/home/ryan/dev/nim/clones/Nim/compiler/pipelines.nim(197) processPipelineModule
/home/ryan/dev/nim/clones/Nim/compiler/sem.nim(876) semWithPContext
/home/ryan/dev/nim/clones/Nim/compiler/sem.nim(838) semStmtAndGenerateGenerics
/home/ryan/dev/nim/clones/Nim/compiler/semstmts.nim(3007) semStmt
/home/ryan/dev/nim/clones/Nim/compiler/semexprs.nim(1208) semExprNoType
/home/ryan/dev/nim/clones/Nim/compiler/semexprs.nim(3553) semExpr
/home/ryan/dev/nim/clones/Nim/lib/system.nim(934) semStmtList
/home/ryan/dev/nim/clones/Nim/compiler/semexprs.nim(3456) semExpr
/home/ryan/dev/nim/clones/Nim/compiler/semexprs.nim(1190) semDirectOp
/home/ryan/dev/nim/clones/Nim/compiler/semexprs.nim(1068) afterCallActions
/home/ryan/dev/nim/clones/Nim/compiler/semexprs.nim(39) semTemplateExpr
/home/ryan/dev/nim/clones/Nim/compiler/sem.nim(482) semAfterMacroCall
/home/ryan/dev/nim/clones/Nim/compiler/semexprs.nim(3553) semExpr
/home/ryan/dev/nim/clones/Nim/lib/system.nim(934) semStmtList
/home/ryan/dev/nim/clones/Nim/compiler/semexprs.nim(3553) semExpr
/home/ryan/dev/nim/clones/Nim/lib/system.nim(934) semStmtList
/home/ryan/dev/nim/clones/Nim/compiler/semexprs.nim(3571) semExpr
/home/ryan/dev/nim/clones/Nim/compiler/semstmts.nim(2738) semProc
/home/ryan/dev/nim/clones/Nim/compiler/semstmts.nim(2575) semProcAux
/home/ryan/dev/nim/clones/Nim/compiler/lookups.nim(381) wrongRedefinition
/home/ryan/dev/nim/clones/Nim/compiler/msgs.nim(589) liMessage
/home/ryan/dev/nim/clones/Nim/compiler/msgs.nim(445) handleError
/home/ryan/dev/nim/clones/Nim/compiler/msgs.nim(421) quit

Expected Output

Known Workarounds

No response

Additional Information

No response

[metagn]

Not related to #14827 etc, this doesn't work either:

proc temp(one: int, two: int, three: int)  =
  discard

template temp(body: typed): untyped =
  body

temp:
  proc a(tp: int) =
    discard

Defining the typed template overload before the proc makes it work, but changing it back to untyped makes it fail again.

Culprit is this I'm guessing:

Nim/compiler/sigmatch.nim

Lines 2819 to 2820 in 79ddb7d

	template noMatch() =
	c.mergeShadowScope #merge so that we don't have to resem for later overloads