"certificate verify failure" with Web::Scraper module - perl

Question

I have the following results in certificate validation problems:
use URI;
use Web::Scraper
my $res = $scraper->scrape( URI->new('https://example.com') );
After waiting about 2 min, I get the following error:
GET https://example.com failed: 500 Can't connect to example.com:443
(certificate verify failed)
Per suggestion in comments, I ran openssl s_client -connect olms.dol-esa.gov:443. It output the following to the terminal instantly and then hung for about 2 minutes:
CONNECTED(00000003)
depth=3 O = Digital Signature Trust Co., CN = DST Root CA X3
verify error:num=19:self signed certificate in certificate chain
verify return:0
---
Certificate chain
0 s:/CN=olms.dol-esa.gov/O=DEPARTMENT OF LABOR/L=Washington/ST=District of Columbia/C=US
i:/C=US/O=IdenTrust/OU=TrustID Server/CN=TrustID Server CA A52
1 s:/C=US/O=IdenTrust/OU=TrustID Server/CN=TrustID Server CA A52
i:/C=US/O=IdenTrust/CN=IdenTrust Commercial Root CA 1
2 s:/C=US/O=IdenTrust/CN=IdenTrust Commercial Root CA 1
i:/O=Digital Signature Trust Co./CN=DST Root CA X3
3 s:/O=Digital Signature Trust Co./CN=DST Root CA X3
i:/O=Digital Signature Trust Co./CN=DST Root CA X3
---
Server certificate
-----BEGIN CERTIFICATE-----
<SNIP>
-----END CERTIFICATE-----
subject=/CN=olms.dol-esa.gov/O=DEPARTMENT OF LABOR/L=Washington/ST=District of Columbia/C=US
issuer=/C=US/O=IdenTrust/OU=TrustID Server/CN=TrustID Server CA A52
---
No client certificate CA names sent
---
SSL handshake has read 6233 bytes and written 615 bytes
---
New, TLSv1/SSLv3, Cipher is DES-CBC3-SHA
Server public key is 2048 bit
Secure Renegotiation IS supported
Compression: NONE
Expansion: NONE
SSL-Session:
Protocol : TLSv1.2
Cipher : DES-CBC3-SHA
Session-ID: 3E5B2FBD819EF7880143C874181B7D67D3B1A0CE7C319B35F276E1CE8D9B9A18
Session-ID-ctx:
Master-Key: BE8A24B0350C48FCC3ECFA21AE896BF09F8978C481F3BE01E1E9B904A0BFB87098914DB6CD592BBC7634142A4B5C43FB
Key-Arg : None
PSK identity: None
PSK identity hint: None
SRP username: None
Start Time: 1486034348
Timeout : 300 (sec)
Verify return code: 19 (self signed certificate in certificate chain)
---
After waiting about two minutes, the following was output:
read:errno=0

Answer 1

Web::Scraper uses LWP::UserAgent. More modern versions of that attempt to verify the hostnames unless you turn off that feature. Something else may be going on, but this question is low in details.
One of the constructor arguments to LWP::UserAgent is:
LWP::UserAgent->new(
ssl_opts => { verify_hostname => 0 }
...;
}
You can construct your own user agent object and give it to Web::Scraper:
my $scraper = Web::Scraper->new(...);
$scraper->user_agent( $your_own_lwp_useragent_object );
Also see the answer at "Perl LWP::Simple HTTPS error". For more help, we'll need version details for the relevant modules and your openssl details.