Nim: import os + use of paramCount and paramStr in config.nims causes "ambiguous call' error

[kaushalmodi]

In config.nims, when the os module is imported and paramCount and/or paramStr are used, we get the "ambiguous call" error (because these two are defined in both system and os.

Example config.nims

import os # commenting this out fixes the error
# import os except paramCount, paramStr # this also does not give that error

task temp123, "Temp task":
  let
    numParams = paramCount()
  for i in 1 .. numParams:
    echo paramStr(i)

Current Output

/home/kmodi/sandbox/nim/aoc2019/config.nims(3, 6) template/generic instantiation of `task` from here
/home/kmodi/sandbox/nim/aoc2019/config.nims(5, 27) Error: ambiguous call; both system.paramCount() [declared in /home/kmodi/usr_local/apps/6/nim/devel/lib/system/nimscript.nim(65, 6)] and os.paramCount() [declared in /home/kmodi/usr_local/apps/6/nim/devel/lib/pure/os.nim(2613, 8)] match for: ()

Expected Output

No error

Workaround

• Use import os except paramCount, paramStr, or system. qualifiers with the ambiguous identifiers.

Additional Information

$ nim -v
Nim Compiler Version 1.1.1 [Linux: amd64]
Compiled at 2019-12-05
Copyright (c) 2006-2019 by Andreas Rumpf

git hash: 3fbb3bfd3f440c059d6290c12834a38a61da98f2
active boot switches: -d:release

This used to work at some point (probably around Nim 19.x).

[genotrance]

We have to do the same thing in nimble as well today.

https://github.com/nim-lang/nimble/blob/master/src/nimblepkg/nimscriptwrapper.nim#L118

[nc-x]

Not a bug? Even outside of nimscript, name clashes are possible and you need to use qualified names.

[kaushalmodi]

Even outside of nimscript, name clashes are possible and you need to use qualified names.

Is this a slightly different case though?

The name clashes are understood when the they happen among two or more user-imported modules.

In this case, it happens between the implicitly imported system and user imported os.

I believe there was already an internal way in the packages to determine if an stdlib module is imported in a NimScript. If so, something special can probably done to prevent this name clash on doing import os.

[SolitudeSF]

os defines param* as error for nimscript and other targets.
Error: unhandled exception: paramCount is not implemented on Nintendo Switch [OSError]
this is clearly not right.

[nc-x]

@kaushalmodi https://github.com/nim-lang/Nim/pull/12860

Please send similar PR for any more such issue :)

[kaushalmodi]

@nc-x Thank you for working on a PR to fix this!

I would have liked to send a PR to fix this myself, but looking at your PR, I don't think I would have been able to make those fixes myself. But I am always trying ..

[nc-x]

@kaushalmodi the original PR was much simpler. It just removed the proc declarations from os.nim for nimscript. And it passed all the tests, unlike now :)