This may be a gdb bug, but anyway...
cat type.f90
program main
type foo
real :: a
integer :: b
end type foo
type(foo) :: q
q = foo(3.14, 42)
print *,q
end program main
$ gfortran -g type.f90
$ gdb ./a.out
GNU gdb 6.3-debian
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i386-linux"...Using host libthread_db library
"/lib/tls/libthread_db.so.1".
(gdb) b type.f90:7
Breakpoint 1 at 0x8048624: file type.f90, line 7.
(gdb) r
Starting program: /home/ig25/Krempel/Gdb/a.out
Breakpoint 1, MAIN__ () at type.f90:7
7 q = foo(3.14, 42)
Current language: auto; currently fortran
(gdb) p q
$1 = Invalid F77 type code 3 in symbol table.
(gdb) q
The program is running. Exit anyway? (y or n) y
--
Summary: derived types not displayed correctly
Product: gcc
Version: 4.1.0
Status: UNCONFIRMED
Keywords: wrong-debug
Severity: normal
Priority: P2
Component: fortran
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: tkoenig at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24527
