script which creates the certificate db:

#!/bin/sh

DB="$(pwd)/db"

echo "### reinit $DB"
rm -rf "$DB"
mkdir "$DB"

set -ex
certutil -d "$DB" -N
certutil -d "$DB" -t "CT,C,C" -n test1   -S -s "CN=test1" -x -v 24
certutil -d "$DB" -t "CT,C,C" -n test2   -S -s "CN=test2" -x -v 24
certutil -d "$DB" -t "CT,C,C" -n test3   -S -s "CN=test3" -x -v 24
certutil -d "$DB" -t "CT,C,C" -n fedora  -A -i ~/.fedora.cert
certutil -d "$DB" -L

Fixed by upstream commit e1ec222.

commit e1ec222e8bdf4b02f511666656ce1d6bd60d0988
Author: Alon Levy <alevy>
Date:   Fri Mar 4 09:36:49 2011 +0200

    client/smartcard: handle the --smartcard-db option

diff --git a/client/application.cpp b/client/application.cpp
index ea88dc5..9257eb2 100644
--- a/client/application.cpp
+++ b/client/application.cpp
@@ -2271,7 +2271,7 @@ bool Application::process_cmd_line(int argc, char** argv, bool &full_screen)
     parser.add(SPICE_OPT_SMARTCARD_CERT, "smartcard-cert", "Use virtual reader+card with given cert(s)",
         "smartcard-cert", true);
     parser.set_multi(SPICE_OPT_SMARTCARD_CERT, ',');
-    parser.add(SPICE_OPT_SMARTCARD_DB, "smartcard-db", "Use given db for smartcard certs");
+    parser.add(SPICE_OPT_SMARTCARD_DB, "smartcard-db", "Use given db for smartcard certs", "smartcard-db", true);
 #endif
 
     for (int i = SPICE_CHANNEL_MAIN; i < SPICE_END_CHANNEL; i++) {
@@ -2395,6 +2395,9 @@ bool Application::process_cmd_line(int argc, char** argv, bool &full_screen)
                     _smartcard_options->certs.end(), std::string(val));
             } while ((val=parser.next_argument()));
             break;
+        case SPICE_OPT_SMARTCARD_DB:
+            _smartcard_options->dbname = val;
+            break;
 #endif
         case CmdLineParser::OPTION_HELP:
             parser.show_help();

VERIFIED in spice-client-0.8.2-7.el6.x86_64

    Technical note added. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    New Contents:
Cause
    The --smartcard-db client command line option was not handled.
Consequence
    Using --smartcard-db on the client results in an error message Error: unhandled exception: cmd line error.
Fix
    Handle the --smartcard-db option
Result
    "--smartcard-db" is now handled.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHBA-2011-1518.html