toSeq(bar()) doesn't call bar() depending on unrelated code

[timotheecour]

Example

when true:
  import sequtils
  iterator myIter(): auto {.closure.} =
    yield 1
    yield 2
  proc bar(): auto =
    doAssert false
    myIter
  echo "z1"
  echo toSeq(myIter) # comment this and bug goes away
  echo "z2"
  echo toSeq(bar())

Current Output

z1
@[1, 2]
z2
@[1, 2]

Expected Output

doAssert false called

Additional Information

devel 1.5.1 0d0e434
(timotheecour#322 would avoid this issue and all other issues with toSeq)

[metagn]

expandMacros output:

import
  sequtils

iterator myIter(): auto {.closure.} =
  yield 1
  yield 2

proc bar(): auto =
  result =
    const
      expr`gensym0 = "false"
    const
      loc`gensym1 = (filename: "/usercode/in.nim", line: 9, column: 13)
      ploc`gensym1 = "/usercode/in.nim(9, 14)"
    {.line: (filename: "/usercode/in.nim", line: 9, column: 13).}:
      if true:
        failedAssertImpl("/usercode/in.nim(9, 14) `false` ")
    myIter

echo ["z1"]
echo [
  template iter2_4950003(): untyped =
    myIter()
  
  type
    OutType`gensym8 = typeof(iter2())
  var result`gensym8: seq[OutType`gensym8] = @[]
  for x`gensym8 in myIter():
    add(result`gensym8, x`gensym8)
  result`gensym8]
echo ["z2"]
echo [
  template iter2_5040003(): untyped =
    bar()()
  
  type
    OutType`gensym23 = typeof(iter2())
  var result`gensym23: seq[OutType`gensym23] = @[]
  for x`gensym23 in myIter():
    add(result`gensym23, x`gensym23)
  result`gensym23]