Concept proc resolution issue with `posix.read`

[euantorano]

The following code reports false, true when the expected result is true, true:

import os, posix

type
    Reader = concept c
        c.read(openarray[byte], int, int) is int
        
    Rdr = concept c
        c.rd(openarray[byte], int, int) is int
        
type
    TestFile = object
    
proc read(r: TestFile, dest: openarray[byte], offset: int, limit: int): int =
    result = 0
    
proc rd(r: TestFile, dest: openarray[byte], offset: int, limit: int): int =
    result = 0
    
when isMainModule:
    echo TestFile is Reader, ", ", TestFile is Rdr

However, if you exclude posix.read from being imported it works:

import os
import posix except read

type
    Reader = concept c
        c.read(openarray[byte], int, int) is int
        
    Rdr = concept c
        c.rd(openarray[byte], int, int) is int
        
type
    TestFile = object
    
proc read(r: TestFile, dest: openarray[byte], offset: int, limit: int): int =
    result = 0
    
proc rd(r: TestFile, dest: openarray[byte], offset: int, limit: int): int =
    result = 0
    
when isMainModule:
    echo TestFile is Reader, ", ", TestFile is Rdr

Another interesting case is the following:

import os
from posix import nil

type
    Reader = concept c
        c.read(openarray[byte], int, int) is int
        
    Rdr = concept c
        c.rd(openarray[byte], int, int) is int
        
    Closer = concept c
        c.close()
        
type
    TestFile = object
    
proc read(r: TestFile, dest: openarray[byte], offset: int, limit: int): int =
    result = 0
    
proc rd(r: TestFile, dest: openarray[byte], offset: int, limit: int): int =
    result = 0
    
proc close(r: TestFile) =
    discard
    
when isMainModule:
    echo TestFile is Reader, ", ", TestFile is Rdr
    echo TestFile is Closer

I would expect an output of

true, true
true

But instead get

true, true
false

Perhaps this second case is a misunderstanding on my part...