Borrow . in distinct generic types generates bad c code

[jxy]

With the code

type G[A] = object
  v:A
type F {.borrow: `.`.} = distinct G

var g = G[int](v:1)
var f = F(g)
echo g.v
echo f.v

using compiler

Nim Compiler Version 0.17.1 (2017-06-30) [MacOSX: amd64]
Copyright (c) 2006-2017 by Andreas Rumpf

git hash: 4de989d1c5e69393e3ac14fa0516203d0d06773a
active boot switches: -d:release

The c compiler complaints about the bad c code.

$ nim c t.nim    
Hint: used config file '/Users/jin/pkg/src/Nim-devel/config/nim.cfg' [Conf]
Hint: system [Processing]
Hint: t [Processing]
CC: tmp_t
CC: stdlib_system
Error: execution of an external compiler program 'clang -c  -w  -I/Users/jin/pkg/src/Nim-devel/lib -o /Users/jin/tmp/nimcache/tmp_t.o /Users/jin/tmp/nimcache/tmp_t.c' failed with exit code: 1

/Users/jin/tmp/nimcache/tmp_t.c:133:27: error: assigning to 'G_No3p5m0ZKtGo56MF2jraGw' (aka 'struct G_No3p5m0ZKtGo56MF2jraGw') from incompatible type 'G_jdHvP31usBP9cMk9aMPWrjVA' (aka 'struct G_jdHvP31usBP9cMk9aMPWrjVA')
        f_cJwUcqUYRCv7qhxy0Ko3Bg = g_gzmpjI9cnOVgSdyajRkwuzw;
                                 ^ ~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.

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[jxy]

It still results in the wrong C code.

[jxy]

It still generates the wrong C code.

[bung87]

without the borrow, it result to same error, looks invalid to me, as F lose generic param.

type G[A] = object
  v:A
type F = distinct G
var g = G[int](v:1)
var f = F(g)

well after making this works, I starting to think below doesn't make much sense. for borrowing properties

type G[A] = object
  v:A
type F[T] {.borrow: `.`.} = distinct G[T]

var g = G[int](v:1)
var f = F[int](g)
echo g.v
echo f.v