On ia64, gdb 8.2.1 fails to build from source:

make[9]: Leaving directory '/<<PKGBUILDDIR>>/build/objdir/gdb/build-gnulib/import'
make[8]: Leaving directory '/<<PKGBUILDDIR>>/build/objdir/gdb/build-gnulib/import'
make[7]: Leaving directory '/<<PKGBUILDDIR>>/build/objdir/gdb/build-gnulib/import'
make[6]: Leaving directory '/<<PKGBUILDDIR>>/build/objdir/gdb/build-gnulib'
make[5]: Leaving directory '/<<PKGBUILDDIR>>/build/objdir/gdb/build-gnulib'
make[4]: Leaving directory '/<<PKGBUILDDIR>>/build/objdir/gdb'
  CXX    gdb.o
  CXX    ia64-tdep.o
  CXX    ia64-linux-tdep.o
/<<PKGBUILDDIR>>/gdb/ia64-tdep.c: In function ‘LONGEST getunwind_table(gdb_byte**)’:
/<<PKGBUILDDIR>>/gdb/ia64-tdep.c:2664:16: error: too many arguments to function ‘gdb::optional<std::vector<unsigned char, gdb::default_init_allocator<unsigned char, std::allocator<unsigned char> > > > target_read_alloc(target_ops*, target_object, const char*)’
     NULL, buf_p);
                ^
In file included from /<<PKGBUILDDIR>>/gdb/inferior.h:41,
                 from /<<PKGBUILDDIR>>/gdb/ia64-tdep.c:21:
/<<PKGBUILDDIR>>/gdb/target.h:341:40: note: declared here
 extern gdb::optional<gdb::byte_vector> target_read_alloc
                                        ^~~~~~~~~~~~~~~~~
/<<PKGBUILDDIR>>/gdb/ia64-tdep.c:2664:16: error: cannot convert ‘gdb::optional<std::vector<unsigned char, gdb::default_init_allocator<unsigned char, std::allocator<unsigned char> > > >’ to ‘LONGEST’ {aka ‘long int’} in assignment
     NULL, buf_p);
                ^
make[3]: *** [Makefile:1622: ia64-tdep.o] Error 1
make[3]: *** Waiting for unfinished jobs....
make[3]: Leaving directory '/<<PKGBUILDDIR>>/build/objdir/gdb'
make[2]: *** [Makefile:8491: all-gdb] Error 2
make[2]: Leaving directory '/<<PKGBUILDDIR>>/build/objdir'
make[1]: *** [Makefile:850: all] Error 2
make[1]: Leaving directory '/<<PKGBUILDDIR>>/build/objdir'

The full Debian build log can be found at https://buildd.debian.org/status/fetch.php?pkg=gdb&arch=ia64&ver=8.2.1-2&stamp=1555329632&raw=0