An exported converter, is silently exported by intermediate module

[enthus1ast]

Description

An exported converter causes issues later in the import chain. Even if the module a is not exported by b.nim it is still causing issues in c.nim

a.nim

converter toInt*(x: uint8): int = int(x)

proc `$`*(x: uint8): string {.raises: [].} =
  result.addInt(int(x))

b.nim

import a

c.nim

import b
echo 10'u8

Also see:

https://github.com/Vladar4/sdl2_nim/issues/38 https://forum.nim-lang.org/t/8646#56246

Nim Version

Nim Compiler Version 2.0.0 [Linux: amd64] Compiled at 2023-08-01 Copyright (c) 2006-2023 by Andreas Rumpf

git hash: a488067a4130f029000be4550a0fb1b39e0e9e7c active boot switches: -d:release

Current Output

nim c -r c.nim 
Hint: used config file '/home/david/.choosenim/toolchains/nim-2.0.0/config/nim.cfg' [Conf]
Hint: used config file '/home/david/.choosenim/toolchains/nim-2.0.0/config/config.nims' [Conf]
Hint: used config file '/home/david/projects/nimPlayground/config.nims' [Conf]
........................................................................
/home/david/projects/nimPlayground/conv/b.nim(1, 8) Warning: imported and not used: 'a' [UnusedImport]
/home/david/projects/nimPlayground/conv/c.nim(2, 1) Error: type mismatch
Expression: echo 10'u8
  [1] 10'u8: uint8

Expected one of (first mismatch at [position]):
[1] proc echo(x: varargs[typed, `$`])

Expected Output

10

Possible Solution

No response

Additional Information

No response

[awr1]

iirc converters are meant to be non-exportable. this is not mentioned in the manual but i recall some convo on IRC indicating this was the case.

[Araq]

Converters can be exported but the export rules are the same: A direct import makes the converter visible (and implicitly invokable) and an indirect import does not.