"Uninitialised value was created by a stack allocation" with NAG fortran 6.2

I'm getting a very strange behavior with the latest release of the NAG Fortran Compiler Release 6.2(Chiyoda) Build 6214. When using ifort or gfortran is everything ok, and even with NAG Fortran Compiler Release 6.1(Tozai) Build 6136. The following code reproduces the error that I'm getting:

module mod
  type :: type1_t
  end type type1_t

  type :: type2_t
  contains
    procedure, nopass :: proc2
  end type type2_t
contains
  subroutine proc2
    class(type1_t), allocatable :: bug
  end subroutine proc2
end module mod

program main
  use mod
  type(type2_t) :: type2
  call type2 % proc2
end program main

Basically, the problem seems to be in the local variable bug in the procedure proc2. I'm obtaining the following error report when using Valgrind:

==22467== ERROR SUMMARY: 26 errors from 9 contexts (suppressed: 0 from 0)
==22467== 
==22467== 1 errors in context 1 of 9:
==22467== Syscall param write(buf) points to uninitialised byte(s)
==22467==    at 0x5710154: write (write.c:27)
==22467==    by 0x568B1BC: _IO_file_write@@GLIBC_2.2.5 (fileops.c:1203)
==22467==    by 0x568BB2E: new_do_write (fileops.c:457)
==22467==    by 0x568BB2E: _IO_file_xsputn@@GLIBC_2.2.5 (fileops.c:1277)
==22467==    by 0x567F2AE: fputs (iofputs.c:38)
==22467==    by 0x16E42B: write_insertion (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x16FFC7: rt_message_core.constprop.7 (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x17163D: __NAGf90_rterr (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x121CD8: line_deallocate.isra.2 (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x123E98: __NAGf90_laDeAlloc (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x15FEDB: mod_MP_proc2 (test.f90:12)
==22467==    by 0x15FF54: main (test.f90:18)
==22467==  Address 0x1ffeffe969 is on thread 1's stack
==22467==  in frame #4, created by write_insertion (???:)
==22467==  Uninitialised value was created by a stack allocation
==22467==    at 0x15FBA4: mod_MP_proc2 (test.f90:10)
==22467== 
==22467== 
==22467== 1 errors in context 2 of 9:
==22467== Conditional jump or move depends on uninitialised value(s)
==22467==    at 0x4C32CF9: strlen (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==22467==    by 0x567F204: fputs (iofputs.c:33)
==22467==    by 0x16E42B: write_insertion (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x16FFC7: rt_message_core.constprop.7 (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x17163D: __NAGf90_rterr (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x121CD8: line_deallocate.isra.2 (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x123E98: __NAGf90_laDeAlloc (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x15FEDB: mod_MP_proc2 (test.f90:12)
==22467==    by 0x15FF54: main (test.f90:18)
==22467==  Uninitialised value was created by a stack allocation
==22467==    at 0x15FBA4: mod_MP_proc2 (test.f90:10)
==22467== 
==22467== 
==22467== 1 errors in context 3 of 9:
==22467== Use of uninitialised value of size 8
==22467==    at 0x121C48: line_deallocate.isra.2 (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x123E98: __NAGf90_laDeAlloc (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x15FEDB: mod_MP_proc2 (test.f90:12)
==22467==    by 0x15FF54: main (test.f90:18)
==22467==  Uninitialised value was created by a stack allocation
==22467==    at 0x15FBA4: mod_MP_proc2 (test.f90:10)
==22467== 
==22467== 
==22467== 1 errors in context 4 of 9:
==22467== Conditional jump or move depends on uninitialised value(s)
==22467==    at 0x127C63: __NAGf90_cdangling_aDeAlloc (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x15FEDB: mod_MP_proc2 (test.f90:12)
==22467==    by 0x15FF54: main (test.f90:18)
==22467==  Uninitialised value was created by a stack allocation
==22467==    at 0x15FBA4: mod_MP_proc2 (test.f90:10)
==22467== 
==22467== 
==22467== 1 errors in context 5 of 9:
==22467== Use of uninitialised value of size 8
==22467==    at 0x15FEA9: mod_MP_proc2 (test.f90:12)
==22467==    by 0x15FF54: main (test.f90:18)
==22467==  Uninitialised value was created by a stack allocation
==22467==    at 0x15FBA4: mod_MP_proc2 (test.f90:10)
==22467== 
==22467== 
==22467== 1 errors in context 6 of 9:
==22467== Use of uninitialised value of size 8
==22467==    at 0x15FE96: mod_MP_proc2 (test.f90:12)
==22467==    by 0x15FF54: main (test.f90:18)
==22467==  Uninitialised value was created by a stack allocation
==22467==    at 0x15FBA4: mod_MP_proc2 (test.f90:10)
==22467== 
==22467== 
==22467== 1 errors in context 7 of 9:
==22467== Conditional jump or move depends on uninitialised value(s)
==22467==    at 0x15FE90: mod_MP_proc2 (test.f90:12)
==22467==    by 0x15FF54: main (test.f90:18)
==22467==  Uninitialised value was created by a stack allocation
==22467==    at 0x15FBA4: mod_MP_proc2 (test.f90:10)
==22467== 
==22467== 
==22467== 9 errors in context 8 of 9:
==22467== Conditional jump or move depends on uninitialised value(s)
==22467==    at 0x4C32D08: strlen (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==22467==    by 0x567F204: fputs (iofputs.c:33)
==22467==    by 0x16E42B: write_insertion (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x16FFC7: rt_message_core.constprop.7 (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x17163D: __NAGf90_rterr (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x121CD8: line_deallocate.isra.2 (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x123E98: __NAGf90_laDeAlloc (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x15FEDB: mod_MP_proc2 (test.f90:12)
==22467==    by 0x15FF54: main (test.f90:18)
==22467==  Uninitialised value was created by a stack allocation
==22467==    at 0x15FBA4: mod_MP_proc2 (test.f90:10)
==22467== 
==22467== 
==22467== 10 errors in context 9 of 9:
==22467== Conditional jump or move depends on uninitialised value(s)
==22467==    at 0x16EAD1: write_insertion (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x16FFC7: rt_message_core.constprop.7 (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x17163D: __NAGf90_rterr (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x121CD8: line_deallocate.isra.2 (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x123E98: __NAGf90_laDeAlloc (in /home/rcarvalho/Desktop/nagdebug/a.out)
==22467==    by 0x15FEDB: mod_MP_proc2 (test.f90:12)
==22467==    by 0x15FF54: main (test.f90:18)
==22467==  Uninitialised value was created by a stack allocation
==22467==    at 0x15FBA4: mod_MP_proc2 (test.f90:10)
==22467== 
==22467== ERROR SUMMARY: 26 errors from 9 contexts (suppressed: 0 from 0)
Aborted (core dumped)

Any suggestions in understanding this behavior? Or perhaps I'm doing something wrong...

Apparently this problem was already solved in patch 6218, as “possible runtime crash for local polymorphic scalar allocatable with no type parameters, if the local variable is not allocated at some time during execution of the routine."