Not sure what you mean with "not safe". It is quite literally what was requested.
The OP said "We allow to use every possible string and argument after `--job`." For me, that includes the string --job itself.
use Data::Dump;
my @argv = qw/ foo --job X --job Y --job Z /;
my ($args, $job) = split /--job /, join( ' ', @argv );
dd $args, $job;
__END__
("foo ", "X ")
Another one, a command line of --hello "world --job foo" --job bar:
use Data::Dump;
my @argv = ('--hello','world --job foo','--job','bar');
my ($args, $job) = split /--job /, join( ' ', @argv );
dd $args, $job;
__END__
("--hello world ", "foo ")