Bug#1093190: w3c-linkchecker: Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296

[Alexis Huxley]

Package: w3c-linkchecker
Version: 5.0.0-2
Severity: normal

Dear Maintainer,

I ran: 

     checklink https://www.google.com/   

which produces a lot of lines:

	Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
	Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
	...

The problem was present for all other sites I tested. The output is below.
I also ran under 'env -i' to ensure my environment was not triggering this.

Alexis




farfalle$ checklink https://www.google.com/
W3C Link Checker version 5.0.0 (c) 1999-2019 W3C
GET https://www.google.com/  fetched in 1.25 seconds

Processing	https://www.google.com/


Settings used:
- Accept: text/html, application/xhtml+xml;q=0.9, application/vnd.wap.xhtml+xml;q=0.6, */*;q=0.5
- Accept-Language: (not sent)
- Referer: sending
- Cookies: not used
- Upgrade-Insecure-Requets: 1
- Sleeping 1 second between requests to each server
Parsing...
 done (14 lines in 0.02 seconds).
Checking anchors...
 done.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.
Use of uninitialized value $_ in pattern match (m//) at /usr/bin/checklink line 1296.

Checking link https://www.google.com/images/nav_logo229.png
HEAD https://www.google.com/images/nav_logo229.png  fetched in 2.08 seconds

Checking link https://www.youtube.com/?tab=w1
HEAD https://www.youtube.com/?tab=w1  fetched in 1.40 seconds

Checking link https://www.google.com/setprefdomain?prefdom=DE&prev=https://www.google.de/&sig=K_JqWqwPQnJwsvIZD_0InRssPEyTs%3D
HEAD https://www.google.com/setprefdomain?prefdom=DE&prev=https://www.google.de/&sig=K_JqWqwPQnJwsvIZD_0InRssPEyTs%3D  fetched in 1.08 seconds

Checking link https://www.google.de/intl/de/about/products?tab=wh
HEAD https://www.google.de/intl/de/about/products?tab=wh
^C
farfalle$

-- System Information:
Debian Release: 12.9
  APT prefers stable-security
  APT policy: (500, 'stable-security'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 6.1.0-28-amd64 (SMP w/4 CPU threads; PREEMPT)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages w3c-linkchecker depends on:
ii  debconf [debconf-2.0]       1.5.82
ii  libcgi-pm-perl              4.55-1
ii  libconfig-general-perl      2.65-2
ii  libcss-dom-perl             0.17-2
ii  libencode-locale-perl       1.05-3
ii  libhtml-parser-perl         3.81-1
ii  libhttp-cookies-perl        6.10-1
ii  libhttp-message-perl        6.44-1
ii  liblocale-codes-perl        3.73-1
ii  libnet-http-perl            6.22-1
ii  libnet-ip-perl              1.26-3
ii  libterm-readkey-perl        2.38-2+b1
ii  liburi-perl                 5.17-1
ii  libwww-perl                 6.68-1
ii  perl [libencode-perl]       5.36.0-7+deb12u1
ii  perl-base [libsocket-perl]  5.36.0-7+deb12u1
ii  ucf                         3.0043+nmu1+deb12u1

Versions of packages w3c-linkchecker recommends:
ii  apache2 [httpd-cgi]   2.4.62-1~deb12u2
ii  w3c-markup-validator  1.3+dfsg-4

w3c-linkchecker suggests no packages.

-- debconf information:
  w3c-linkchecker/private_ips: false
  w3c-linkchecker/hostname: localhost