The next step is to run the hanging test in isolation to see at which test it stalls (and maybe even see why):

cpan
CPAN> look Net::OpenSSH
$ perl Makefile.PL
$ make
$ perl -Ilib -w t/quoting.t
[download]

Still seems to get stuck, and no error so far. Its been running for ~45 minutes now and no progress.

-bash-3.2$ sudo cpan
Password: 
Terminal does not support AddHistory.

cpan shell -- CPAN exploration and modules installation (v1.9402)
Enter 'h' for help.

cpan[1]> look Net::OpenSSH
CPAN: Storable loaded ok (v2.20)
Going to read '/usr/local/home/myuser/.cpan/Metadata'
  Database was generated on Fri, 11 Mar 2016 19:17:02 GMT
Running look for module 'Net::OpenSSH'

Trying to open a subshell in the build directory...
CPAN: Data::Dumper loaded ok (v2.124)
'YAML' not installed, falling back to Data::Dumper and Storable to rea
+d prefs '/usr/local/home/myuser/.cpan/prefs'
CPAN: Digest::SHA loaded ok (v5.47)
CPAN: Compress::Zlib loaded ok (v2.02)
Checksum for /usr/local/home/myuser/.cpan/sources/authors/id/S/SA/SALV
+A/Net-OpenSSH-0.70.tar.gz ok
Scanning cache /usr/local/home/myuser/.cpan/build for sizes
......................................................................
+......DONE
CPAN: Archive::Tar loaded ok (v1.52)
Net-OpenSSH-0.70/
Net-OpenSSH-0.70/sample/
Net-OpenSSH-0.70/sample/mod_perl_openssh.pm
Net-OpenSSH-0.70/sample/login_handler.pl
Net-OpenSSH-0.70/sample/autosudo.pl
Net-OpenSSH-0.70/sample/git_ssh_through_mux.pl
Net-OpenSSH-0.70/sample/change_passwd.pl
Net-OpenSSH-0.70/sample/git_with_password.pl
Net-OpenSSH-0.70/sample/net-telnet.pl
Net-OpenSSH-0.70/sample/expect.pl
Net-OpenSSH-0.70/sample/password_from_data.pl
Net-OpenSSH-0.70/sample/sshfs_mount.pl
Net-OpenSSH-0.70/sample/keep_in_sync.pl
Net-OpenSSH-0.70/Changes
Net-OpenSSH-0.70/lib/
Net-OpenSSH-0.70/lib/Net/
Net-OpenSSH-0.70/lib/Net/OpenSSH/
Net-OpenSSH-0.70/lib/Net/OpenSSH/ShellQuoter/
Net-OpenSSH-0.70/lib/Net/OpenSSH/ShellQuoter/MSCmd.pm
Net-OpenSSH-0.70/lib/Net/OpenSSH/ShellQuoter/fish.pm
Net-OpenSSH-0.70/lib/Net/OpenSSH/ShellQuoter/POSIX.pm
Net-OpenSSH-0.70/lib/Net/OpenSSH/ShellQuoter/Chain.pm
Net-OpenSSH-0.70/lib/Net/OpenSSH/ShellQuoter/csh.pm
Net-OpenSSH-0.70/lib/Net/OpenSSH/ShellQuoter/MSWin.pm
Net-OpenSSH-0.70/lib/Net/OpenSSH/ObjectRemote.pm
Net-OpenSSH-0.70/lib/Net/OpenSSH/Constants.pm
Net-OpenSSH-0.70/lib/Net/OpenSSH/ShellQuoter.pm
Net-OpenSSH-0.70/lib/Net/OpenSSH/ModuleLoader.pm
Net-OpenSSH-0.70/lib/Net/OpenSSH/OSTracer.pm
Net-OpenSSH-0.70/lib/Net/OpenSSH/ConnectionCache.pm
Net-OpenSSH-0.70/lib/Net/OpenSSH/SSH.pm
Net-OpenSSH-0.70/lib/Net/OpenSSH.pm
Net-OpenSSH-0.70/t/
Net-OpenSSH-0.70/t/common.pm
Net-OpenSSH-0.70/t/known_hosts
Net-OpenSSH-0.70/t/uri.t
Net-OpenSSH-0.70/t/test_server_key.pub
Net-OpenSSH-0.70/t/test_user_key
Net-OpenSSH-0.70/t/test_user_key.pub
Net-OpenSSH-0.70/t/1_run.t
Net-OpenSSH-0.70/t/test_server_key
Net-OpenSSH-0.70/t/quoting.t
Net-OpenSSH-0.70/patches/
Net-OpenSSH-0.70/patches/openssh-fwd-stdio-to-streamlocal-1.patch
Net-OpenSSH-0.70/Makefile.PL
Net-OpenSSH-0.70/README
Net-OpenSSH-0.70/MANIFEST
Net-OpenSSH-0.70/META.yml
Net-OpenSSH-0.70/META.json
CPAN: File::Temp loaded ok (v0.22)
Working directory is /usr/local/home/myuser/.cpan/build/Net-OpenSSH-0.
+70-ARY6NC
# perl Makefile.PL
Checking if your kit is complete...
Looks good
Generating a Unix-style Makefile
Writing Makefile for Net::OpenSSH
Writing MYMETA.yml and MYMETA.json
# make
cp lib/Net/OpenSSH/ConnectionCache.pm blib/lib/Net/OpenSSH/ConnectionC
+ache.pm
cp lib/Net/OpenSSH/ShellQuoter/fish.pm blib/lib/Net/OpenSSH/ShellQuote
+r/fish.pm
cp lib/Net/OpenSSH/ShellQuoter/POSIX.pm blib/lib/Net/OpenSSH/ShellQuot
+er/POSIX.pm
cp lib/Net/OpenSSH/ShellQuoter.pm blib/lib/Net/OpenSSH/ShellQuoter.pm
cp lib/Net/OpenSSH/ModuleLoader.pm blib/lib/Net/OpenSSH/ModuleLoader.p
+m
cp lib/Net/OpenSSH/ShellQuoter/Chain.pm blib/lib/Net/OpenSSH/ShellQuot
+er/Chain.pm
cp lib/Net/OpenSSH/Constants.pm blib/lib/Net/OpenSSH/Constants.pm
cp lib/Net/OpenSSH/SSH.pm blib/lib/Net/OpenSSH/SSH.pm
cp lib/Net/OpenSSH/ShellQuoter/MSWin.pm blib/lib/Net/OpenSSH/ShellQuot
+er/MSWin.pm
cp lib/Net/OpenSSH/ShellQuoter/MSCmd.pm blib/lib/Net/OpenSSH/ShellQuot
+er/MSCmd.pm
cp lib/Net/OpenSSH.pm blib/lib/Net/OpenSSH.pm
cp lib/Net/OpenSSH/OSTracer.pm blib/lib/Net/OpenSSH/OSTracer.pm
cp lib/Net/OpenSSH/ShellQuoter/csh.pm blib/lib/Net/OpenSSH/ShellQuoter
+/csh.pm
cp lib/Net/OpenSSH/ObjectRemote.pm blib/lib/Net/OpenSSH/ObjectRemote.p
+m
Manifying 7 pod documents
# perl -Ilib -w t/quoting.t
[download]

That testing script runs some commands in order to find which shells are available on your system. One of those commands is not behaving as expected and not returning control back to the the testing script.

Could you run the following Perl code and post here the output:

$|=1;
for (qw(sh csh bash tcsh ksh dash ash pdksh mksh zsh fish)) {
  print "shell: $_\n";
  system $_ => '-c', 'echo good';
}
[download]