为什么我的Perl测试不正确？

Question

我创建了以下测试类：

package Test::DB; 

# $Id$ 
# 

use strict; 
use warnings; 

our $VERSION = '0.01'; 

use Carp; 
use English '-no_match_vars'; 
use Test::Most; 

use base 'Test::Class'; 

sub startup : Tests(startup) { 
    eval { 
     require esp_libs_db; 

     esp_libs_db->import; 

     1; 
    } or Carp::croak($EVAL_ERROR); 

    return 1; 
} 

sub connect : Tests(2) { 
    can_ok 'esp_libs_db', 'espDbConnect'; 

    my $schema = 'test_schema'; 

    throws_ok { espDbConnect($schema) } 
     qr/Cannot locate database ($schema) connection file./, 
     'dies when connection file does not exist'; 

    return 1; 
} 

1; 

当我来到运行测试，我得到以下的输出：

t/run.t .. 
# 
# Test::DB->connect 
1..2 
ok 1 - esp_libs_db->can('espDbConnect') 
not ok 2 - dies when connection file does not exist 

# Failed test 'dies when connection file does not exist' 
# at t/tests/Test/DB.pm line 39. 
# (in Test::DB->connect) 
# expecting: Regexp ((?-xism:Cannot locate database (test_schema) connection file.)) 
# found: <FONT color=red size=4 face=arial>ERROR: PM_DB_0004: Cannot locate database (test_schema) connection file.</FONT> at t/tests/Test/DB.pm line 38 
# Looks like you failed 1 test of 2. 
Dubious, test returned 1 (wstat 256, 0x100) 
Failed 1/2 subtests 

Test Summary Report 
------------------- 
t/run.t (Wstat: 256 Tests: 2 Failed: 1) 
    Failed test: 2 
    Non-zero exit status: 1 
Files=1, Tests=2, 3 wallclock secs (0.44 usr 0.07 sys + 2.44 cusr 0.43 csys = 3.38 CPU) 
Result: FAIL 

我不明白为什么第二次测试失败时，它应该相当显然通过正则表达式

Answer 1

(和)是特殊字符，尝试逃离他们：

qr/Cannot locate database \($schema\) connection file./