$ cat test.asm
%define list "", ""
%xdefine list list, "abc", "123"
%xdefine list list, "def", "456"

%error list
$ nasm -v
NASM version 2.15rc0 compiled on Oct 17 2019
$ nasm test.asm
test.asm:5: error: list, "def", "456"
$ patnasm -v
NASM version 2.15rc0 compiled on Oct 17 2019
$ patnasm test.asm
test.asm:5: error: "", "", "abc", "123", "def", "456"
$ oldnasm -v
NASM version 2.14.03rc2 compiled on Aug 31 2019
$ oldnasm test.asm
test.asm:5: error: "", "", "abc", "123", "def", "456"
$ 


$ cat test2.asm
%push ROOT
%define %$namelist "", ""
%xdefine %$namelist %$namelist, "abc", "123"
%error %$namelist
%pop
$ nasm test2.asm
test2.asm:4: error: "", "abc", "123"
$ patnasm test2.asm
test2.asm:4: error: "", "", "abc", "123"
$ oldnasm test2.asm
test2.asm:4: error: "", "", "abc", "123"
$ cat test3.asm
%define list "", ""
%xdefine list list, "abc", "123"

%error list
$ nasm test3.asm
test3.asm:4: error: list, "abc", "123"
$ patnasm test3.asm
test3.asm:4: error: "", "", "abc", "123"
$ oldnasm test3.asm
test3.asm:4: error: "", "", "abc", "123"
$ 


$ cat test4.asm
%push ROOT
%define %$namelist "", ""
%xdefine %$namelist %$namelist, "abc", "123"
%xdefine %$namelist %$namelist, "def", "456"
%error %$namelist
%pop
$ nasm test4.asm
test4.asm:5: error: "", "def", "456"
$ patnasm test4.asm
test4.asm:5: error: "", "", "abc", "123", "def", "456"
$ oldnasm test4.asm
test4.asm:5: error: "", "", "abc", "123", "def", "456"
$