When using the - - debug flag to build source on Linux/ia32, and then compiling on Linux/ia64 also with the - -debug flag, the variables are invisible to the debugger.
Starting program: /usr/local/src/euphoria/ia64-debug/eui -i /usr/local/src/euphoria/include -D DEBUG /usr/local/src/euphoria/source/euc.ex -debug -build-dir "/usr/local/src/euphoria/ia64-debug/bind-build" -c "/usr/local/src/euphoria/ia64-debug/eu.cfg" -o "/usr/local/src/euphoria/ia64-debug/eubind" -lib "/usr/local/src/euphoria/ia64-debug/eu.a" -makefile -eudir /usr/local/src/euphoria -cflags "-DEX86_64 -m64 -pthread -c -fsigned-char -DEUNIX -ffast-math -g3 -O0 -Wall -I/usr/local/src/euphoria/source -I/usr/local/src/euphoria -DARCH=ix86_64 -DEREL_TYPE="development"" /usr/local/src/euphoria/source/eubind.ex
warning: no loadable sections found in added symbol-file system-supplied DSO at 0x7ffff7ffa000
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Program received signal SIGSEGV, Segmentation fault.
0x000000000071b44b in _62my_sscanf ()
(gdb) l
1171 else{
1172 DeRef(_26803);
1173 _26803 = NOVALUE;
1174 }
1175 // SubProg Cleanup pc: 156 op: STARTLINE (58)
1176
1177 /** error.e:207 screen_output(STDERR, GetMsgText(PRESS_ENTER,0))*/
1178 // SubProg Cleanup pc: 158 op: GLOBAL_INIT_CHECK (109)
1179 // SubProg Cleanup pc: 160 op: GLOBAL_INIT_CHECK (109)
1180 // SubProg Cleanup pc: 162 op: PROC (27)
(gdb) p _26803
No symbol "_26803" in current context.
This is a problem with the C platform and not with the Euphoria programs itself. It's a pretty bad issue but there is no real way to remedy this.