Generic model do not compile

[Clonkk]

When trying to use generics with ref object of Mode l Iget a compile time error :

/home/rcaillaud/Workspace/localws/norm/src/norm/sqlite.nim(86, 22) template/generic instantiation of `hasCustomPragma` from here
/home/rcaillaud/.choosenim/toolchains/nim-1.6.2/lib/core/macros.nim(1529, 25) Error: node is not a symbol

The problem is easy to reproduce :

import norm/[sqlite, model]
import std/os

type A[T] = ref object of Model
  a: int

putEnv(dbHostEnv, "my.db")

proc main() =
  withDb:
    var a = new(A[int])
    db.createTables(a)

main()

This happens even if the generic parameters is not a field. I know the error actually comes from hasCustomPragmas (you can reproduce outside of norm, so it's not strictly speaking a norm issue) but I was wondering if there was a known solution to this ?

[Clonkk]

I dig more into this and it is not a Norm limitation - unless Norm implement its own hasCustomPragma proc to solve this.

See nim-lang/Nim#19427 for more info

[Clonkk]

Reopening because the current fix devel (nim-lang/Nim#19427) is not sufficient

[Clonkk]

Follow up that should fix generic model in nim-lang/Nim#19451.

@moigagoo Considering these changes will not land in 1.6.X would you be in favor of a local hasCustomPragma / getCustomPragmaVal fixed (that would be the working devel version) with something like :

when (NimMajor, NimMinor) <= (1, 6):
  import macros except hasCustomPragma, getCustomPragmaVal
  export macros
  #TODO fetch current custom pragmas proc from devel macros.nim
else:
  import macros
  export macros

It's not the prettiest but it would allow generic model in Norm to work with latest Nim LTS.