perl eval throwing blank exception - exception

Question

I am updating a few records in database. And all the processing is done in eval block.
The problem is that even if the records are successfully updated , I still see a exception being raised.
To debug the exception, I tried printing it using Data Dumper but the exception is blank.
Can any one please help me identify what is this error and why is it thrown every time ?
Environment Details (Perl 5.8 and Unix SUSE)
Dump from Data Dumper:
$VAR1 = '
';
I am using various internal APIs, to update these records.. so I have modified my code to look similar:
sub main{
eval{
DB->updateRecord($value)
};
if($#){
Mail->SendMail(__PACKAGE__,$#):
}
}
package DB;
sub updateRecord{
my ($self , $value) = #_;
my $query = "update set column_value = $value ..<update query> ";
API->processQuery($query );
}

Answer 1

Does your code use warnings;?
The symptom your describing indicated that in your code you are passing die the string "\n". My guess would be that in your source you have a line that is trying to die with an error message but your error message was not initialized. It could be something like
my $error;
if (some_test()) {
$error = 'Some String';
}
if (some_other_test()) {
die "$error\n";
}
If some_test() passes but some_other_test() fails the die will report an error containing only a new line. It would also emit an warning if warnings are enabled.
Another possibility is a typo. If you don't use strict; the error variable might not be correct.
my $error = 'Some String';
if ($error) {
#note the typo (transposed ro to or)
die "$erorr\n";
}
Without use strict; this can be an easy mistake to miss.