Use of _ (as var placeholder) inside a template causes XDeclaredButNotUsed hints

[kaushalmodi]

It is typical to do something like (dirName, baseName, _) = splitFile("/a/b") where you do not care about that 3rd element of the tuple.

When that is used outside a template, as expected, the XDeclaredButNotUsed hint is not printed, good.

But when the same code is used inside a template, I get messages like:

Hint: '_`gensym722021' is declared but not used [XDeclaredButNotUsed]
CC: t.nim

Example

import os

template foo() =
  let
    (dirName, baseName, _) = splitFile("/a/b")
  echo dirName
  echo baseName
  echo "The _ causes the XDeclaredButNotUsed hint to appear when this code is in a template"

foo()

let
  (dirName2, baseName2, _) = splitFile("/a/b")
echo dirName2
echo baseName2
echo "When that _ is outside a template, it does not cause that Hint (which should be the case when inside a template too)"

Current Output

/home/kmodi/sandbox/nim/bug_reports/declared_but_not_used/t.nim(5, 25) Hint: '_`gensym543021' is declared but not used [XDeclaredButNotUsed]
Hint:  [Link]
Hint: operation successful (68333 lines compiled; 0.642 sec total; 90.695MiB peakmem; Debug Build) [SuccessX]
Hint: /home/kmodi/sandbox/nim/bug_reports/declared_but_not_used/t  [Exec]
/a
b
The _ causes the XDeclaredButNotUsed hint to appear when this code is in a template
/a
b
When that _ is outside a template, it does not cause that Hint (which should be the case when inside a template too)

Expected Output

The same output, but that Hint should not appear.

Additional Information

$ nim -v
Nim Compiler Version 0.20.99 [Linux: amd64]
Compiled at 2019-08-28
Copyright (c) 2006-2019 by Andreas Rumpf

git hash: 42d2e68bca2d7fce65591ed7c4697ed1ecf86026
active boot switches: -d:release

---

Update (2021/06/10):

I re-confirm this issue on the latest devel:

Nim Compiler Version 1.5.1 [Linux: amd64]
Compiled at 2021-06-10
Copyright (c) 2006-2021 by Andreas Rumpf

git hash: 19918ceb2b099440cd3e43b6d7fff313de6a84a2
active boot switches: -d:release

[kaushalmodi]

Thank you for the fix @bung87 !