Crash related to nested closure iterators

[dawkot]

iterator foo {.closure.} =
  discard

iterator bar {.closure.} =
  var x = iterator =
    var it = foo # crash
    # var it = iterator = discard # compiles

var x = bar

Error: execution of an external compiler program
'gcc.exe -c  -w -mno-ms-bitfields  -IC:\Users\dawkot\.choosenim\toolchains\nim-#devel\lib -ID:\Nim
-o C:\Users\dawkot\nimcache\test_d\test.c.o C:\Users\dawkot\nimcache\test_d\test.c' failed with exit code: 1

C:\Users\dawkot\nimcache\test_d\test.c: In function 'colonanonymous__9aWAU3lwPAOIcoVcbcTZVUg_2':
C:\Users\dawkot\nimcache\test_d\test.c:409:78: error: request for member 'ClE_0' in something not a structure or union
    asgnRef((void**) (&(*colonenvP_).it1.ClE_0), foo_9aWAU3lwPAOIcoVcbcTZVUg_3.ClE_0);
                                                                              ^
C:\Users\dawkot\nimcache\test_d\test.c:410:59: error: request for member 'ClP_0' in something not a structure or union
    (*colonenvP_).it1.ClP_0 = foo_9aWAU3lwPAOIcoVcbcTZVUg_3.ClP_0;
                                                           ^