Docgen issue with runnableExamples on specific usage of anyIt template.

[alaviss]

Example

import std/sequtils

proc foo*(n: seq[int]): bool =
  result = anyIt(n, it == 0)

Current Output

$ nim doc test.nim
Hint: used config file '/etc/nim/nim.cfg' [Conf]
Hint: used config file '/etc/nim/config.nims' [Conf]
Hint: used config file '/etc/nim/nimdoc.cfg' [Conf]
......
sequtils.nim(721, 3) Error: runnableExamples must appear before the first non-comment statement

Additional Information

Any statement before result = will make the bug disappear.

This is causing disruptek/cps docs to not build.

$ nim -v
Nim Compiler Version 1.5.1 [Linux: amd64]
Compiled at 2021-04-24
Copyright (c) 2006-2021 by Andreas Rumpf

git hash: b667e288e27a09ce4f65166fc66a6b713350a9b6
active boot switches: -d:release -d:nimUseLinenoise -d:nativeStackTrace

Bisect shows that a807233 is the first bad commit.

/cc @timotheecour @xflywind

[timotheecour]

yes, it's a regression, but the real cause is #16993 (which is a regression itself)
2 options:

• turn the error into a warning (temporarily), and fix regression: runnableExamples in template should not affect caller #16993 later
• or just fix regression: runnableExamples in template should not affect caller #16993 directly