Hi again, find below part of the apport report with the crash details:

ProblemType: Crash
Architecture: amd64
CurrentDesktop: XFCE
Date: Fri Sep 28 12:09:52 2018
DistroRelease: Ubuntu 18.04
ExecutablePath: /usr/bin/perl
ExecutableTimestamp: 1531923663
ProcCmdline:
 /usr/bin/perl -Mblib -I. -MStorable=dclone -emy\ $t;\ $Storable::recu
+rsion_limit\ =\ -1;\ $t=[$t]\ for\ 1..65000;dclone($t);\ print\ qq/ok
 /
ProcCwd: /home/fusillator/.cpan/build/Storable-3.11-0
 

SegvAnalysis:
 Segfault happened at: 0x7f06465da3dc <store+44>:       callq  0x7f064
+65cd990 <Perl_ptr_table_fetch@plt>
 PC (0x7f06465da3dc) ok
 source "0x7f06465cd990" (0x7f06465cd990) ok
 destination "(%rsp)" (0x7ffe58591ff0) not located in a known VMA regi
+on (needed writable region)!
 Stack memory exhausted (SP below stack segment)
SegvReason: writing unknown VMA
SourcePackage: perl
Stacktrace:
 #0  0x00007f06465da3dc in store (my_perl=my_perl@entry=0x561207a79260
+, cxt=cxt@entry=0x561207c28500, sv=sv@entry=0x5612081808f0) at Storab
+le.xs:4357
         svh = <optimized out>
         ret = <optimized out>
         type = <optimized out>
         pseen = 0x561207c98ef0
 #1  0x00007f06465db7fb in store_ref (my_perl=0x561207a79260, cxt=0x56
+1207c28500, sv=0x5612081808f0) at Storable.xs:2375
         retval = <optimized out>
         is_weak = 0
 #2  0x00007f06465da519 in store (my_perl=my_perl@entry=0x561207a79260
+, cxt=cxt@entry=0x561207c28500, sv=0x561208180938) at Storable.xs:446
+6
         svh = <optimized out>
         ret = <optimized out>
         type = <optimized out>
         pseen = 0x561207c98ef0
...

 #1998 0x00007f06465da519 in store (my_perl=my_perl@entry=0x561207a792
+60, cxt=cxt@entry=0x561207c28500, sv=0x56120818f718) at Storable.xs:4
+466
         svh = <optimized out>
         ret = <optimized out>
         type = <optimized out>
         pseen = 0x561207c98ef0
 #1999 0x00007f06465db11b in store_array (my_perl=0x561207a79260, cxt=
+0x561207c28500, av=0x56120818f700) at Storable.xs:2700
         sav = <optimized out>
         len = 1
         i = 0
         ret = <optimized out>
Title: perl crashed with SIGSEGV in store()
UnreportableReason:
 You have some obsolete package versions installed. Please upgrade the
+ following packages and check if the problem still occurs:
 
 gcc-8-base, libgcc1
UpgradeStatus: Upgraded to bionic on 2018-08-18 (40 days ago)
_MarkForUpload: True
[download]

I run cpan with a user without the permission to write on the system lib directories, apart those in his home:

$ ls -ld $(perl -e 'print join("\n",@INC)')
ls: cannot access '/usr/local/lib/x86_64-linux-gnu/perl/5.26.1': No su
+ch file or directory
ls: cannot access '/usr/local/share/perl/5.26.1': No such file or dire
+ctory
ls: cannot access '/usr/local/lib/site_perl': No such file or director
+y
drwxr-xr-x  1 root       root         20 ago 18 18:44 /etc/perl
drwxrwxr-x 11 fusillator fusillator 4096 lug 24 16:20 /home/fusillator
+/perl5/lib/perl5
drwxrwxr-x 26 fusillator fusillator 4096 set 28 12:10 /home/fusillator
+/perl5/lib/perl5/x86_64-linux-gnu-thread-multi
lrwxrwxrwx  1 root       root          6 lug 18 16:21 /usr/lib/x86_64-
+linux-gnu/perl/5.26 -> 5.26.1
drwxr-xr-x  1 root       root        272 ago 18 18:51 /usr/lib/x86_64-
+linux-gnu/perl5/5.26
drwxr-xr-x  1 root       root        844 ago 18 18:32 /usr/lib/x86_64-
+linux-gnu/perl-base
drwxr-xr-x  1 root       root        510 ago 18 18:51 /usr/share/perl5
lrwxrwxrwx  1 root       root          6 lug 18 16:21 /usr/share/perl/
+5.26 -> 5.26.1
$ ls -ld /usr/share/perl/5.26.1/
drwxr-xr-x 1 root root 2670 ago 18 18:32 /usr/share/perl/5.26.1/
[download]

here's my cpan configuration (a default one):

$CPAN::Config = {
  'applypatch' => q[/usr/bin/applypatch],
  'auto_commit' => q[0],
  'build_cache' => q[100],
  'build_dir' => q[/home/fusillator/.cpan/build],
  'build_dir_reuse' => q[0],
  'build_requires_install_policy' => q[yes],
  'bzip2' => q[/bin/bzip2],
  'cache_metadata' => q[1],
  'check_sigs' => q[0],
  'colorize_output' => q[0],
  'commandnumber_in_prompt' => q[1],
  'connect_to_internet_ok' => q[1],
  'cpan_home' => q[/home/fusillator/.cpan],
  'ftp_passive' => q[1],
  'ftp_proxy' => q[],
  'getcwd' => q[cwd],
  'gpg' => q[/usr/bin/gpg],
  'gzip' => q[/bin/gzip],
  'halt_on_failure' => q[0],
  'histfile' => q[/home/fusillator/.cpan/histfile],
  'histsize' => q[100],
  'http_proxy' => q[],
  'inactivity_timeout' => q[0],
  'index_expire' => q[1],
  'inhibit_startup_message' => q[0],
  'keep_source_where' => q[/home/fusillator/.cpan/sources],
  'load_module_verbosity' => q[none],
  'make' => q[/usr/bin/make],
  'make_arg' => q[],
  'make_install_arg' => q[],
  'make_install_make_command' => q[/usr/bin/make],
  'makepl_arg' => q[INSTALLDIRS=site],
  'mbuild_arg' => q[],
  'mbuild_install_arg' => q[],
  'mbuild_install_build_command' => q[./Build],
  'mbuildpl_arg' => q[--installdirs site],
  'no_proxy' => q[],
  'pager' => q[/usr/bin/less],
  'patch' => q[/usr/bin/patch],
  'perl5lib_verbosity' => q[none],
  'plugin_list' => [],
  'prefer_external_tar' => q[1],
  'prefer_installer' => q[MB],
  'prefs_dir' => q[/home/fusillator/.cpan/prefs],
  'prerequisites_policy' => q[follow],
  'recommends_policy' => q[1],
  'scan_cache' => q[atstart],
  'shell' => q[/bin/bash],
  'show_unparsable_versions' => q[0],
  'show_upload_date' => q[0],
  'show_zero_versions' => q[0],
  'suggests_policy' => q[0],
  'tar' => q[/bin/tar],
  'tar_verbosity' => q[none],
  'term_is_latin' => q[1],
  'term_ornaments' => q[1],
  'test_report' => q[0],
  'trust_test_report_history' => q[0],
  'unzip' => q[/usr/bin/unzip],
  'urllist' => [q[http://cpan.metacpan.org/], q[http://cpan.metacpan.o
+rg/], q[http://mirror.liquidtelecom.com/CPAN/]],
  'use_prompt_default' => q[0],
  'use_sqlite' => q[0],
  'version_timeout' => q[15],
  'wget' => q[/usr/bin/wget],
  'yaml_load_code' => q[0],
  'yaml_module' => q[YAML],
};
1;
__END__
[download]

Let me know if further details could be useful. thanks Luca