nim-devel regression: Nested generic types construction via template cannot instantiate

[jangko]

Description

import
  std/options

type
  BID = string or uint64

  Future[T] = ref object of RootObj
    internalValue: T

  InternalRaisesFuture[T] = ref object of Future[T]

proc newInternalRaisesFutureImpl[T](): InternalRaisesFuture[T] =
  let fut = InternalRaisesFuture[T]()

template newFuture[T](): auto =
  newInternalRaisesFutureImpl[T]()

proc problematic(blockId: BID): Future[Option[seq[int]]] =
  let resultFuture = newFuture[Option[seq[int]]]()
  return resultFuture

let x = problematic("latest")

Nim Version

Nim Compiler Version 2.1.1 [Windows: amd64] Compiled at 2024-01-23 Copyright (c) 2006-2024 by Andreas Rumpf

git hash: be0b8472130112ad570a6720a0e3a34e67936619 active boot switches: -d:release

Current Output

...\bug.nim(22, 20) template/generic instantiation of `problematic` from here
...\bug.nim(19, 38) Error: cannot instantiate Option [type declared in ...\nim\lib\pure\options.nim(91, 3)]
got: <T>
but expected: <T>

Expected Output

no error

Possible Solution

No response

Additional Information

This code is part of nim-chronos, and it works fine with nim 1.6.18 and nim 2.0.3