follow adduser's changes in example: --gecos => --comment

Considered References:
https://www.debian.org/releases/bookworm/amd64/release-notes/ch-information.en.html#adduser-changes
/usr/share/doc/adduser/NEWS.Debian.gz (from adduser v3.134)
https://manpages.debian.org/bookworm/adduser/adduser.8.en.html

mmdebstrap

@@ -5963,8 +5963,6 @@ sub main() {
     my $sigset = POSIX::SigSet->new(SIGINT, SIGHUP, SIGPIPE, SIGTERM);
     POSIX::sigprocmask(SIG_BLOCK, $sigset) or error "Can't block signals: $!";
 
-    my $pid;
-
     # a pipe to transfer the final tarball from the child to the parent
     pipe my $rfh, my $wfh;
 
@@ -5979,9 +5977,8 @@ sub main() {
     #   b) it puts code writing the protocol outside of the helper/listener
     #   c) the forked listener process cannot communicate to its parent
     pipe my $nblkreader, my $nblkwriter or error "pipe failed: $!";
-    if ($options->{mode} eq 'unshare') {
-        $pid = get_unshare_cmd(
-            sub {
+
+    my $worker = sub {
         # child
         local $SIG{'INT'}  = 'DEFAULT';
         local $SIG{'HUP'}  = 'DEFAULT';
@@ -6013,8 +6010,8 @@ sub main() {
 
         if ($options->{dryrun}) {
             info "simulate creating tarball...";
-                } elsif (any { $_ eq $options->{format} }
-                    ('tar', 'squashfs', 'ext2')) {
+        } elsif (any { $_ eq $options->{format} } ('tar', 'squashfs', 'ext2'))
+        {
             info "creating tarball...";
 
             # redirect tar output to the writing end of the pipe so
@@ -6030,92 +6027,27 @@ sub main() {
                 print $devtar;
             }
 
+            if ($options->{mode} eq 'unshare') {
                 # pack everything except ./dev
                 0 == system('tar', @taropts, '-C', $options->{root}, '.')
                   or error "tar failed: $?";
-
-                    info "done";
-                } elsif (any { $_ eq $options->{format} }
-                    ('directory', 'null')) {
-                    # nothing to do
-                } else {
-                    error "unknown format: $options->{format}";
-                }
-
-                exit 0;
-            },
-            \@idmap
-        );
-    } elsif (any { $_ eq $options->{mode} }
-        ('root', 'fakechroot', 'chrootless')) {
-        $pid = fork() // error "fork() failed: $!";
-        if ($pid == 0) {
-            local $SIG{'INT'}  = 'DEFAULT';
-            local $SIG{'HUP'}  = 'DEFAULT';
-            local $SIG{'PIPE'} = 'DEFAULT';
-            local $SIG{'TERM'} = 'DEFAULT';
-
-            # unblock all delayed signals (and possibly handle them)
-            POSIX::sigprocmask(SIG_UNBLOCK, $sigset)
-              or error "Can't unblock signals: $!";
-
-            close $rfh;
-            close $parentsock;
-            open(STDOUT, '>&', STDERR) or error "cannot open STDOUT: $!";
-
-            setup($options);
-
-            print $childsock (pack('n', 0) . 'adios');
-            $childsock->flush();
-
-            close $childsock;
-
-            close $nblkreader;
-            if (!$options->{dryrun} && $options->{format} eq 'ext2') {
-                my $numblocks = approx_disk_usage($options->{root});
-                print $nblkwriter $numblocks;
-                $nblkwriter->flush();
-            }
-            close $nblkwriter;
-
-            if ($options->{dryrun}) {
-                info "simulate creating tarball...";
-            } elsif (any { $_ eq $options->{format} }
-                ('tar', 'squashfs', 'ext2')) {
-                info "creating tarball...";
-
-                # redirect tar output to the writing end of the pipe so that
-                # the parent process can capture the output
-                open(STDOUT, '>&', $wfh) or error "cannot open STDOUT: $!";
-
-                # Add ./dev as the first entries of the tar file.
-                # We cannot add them after calling tar, because there is no way
-                # to prevent tar from writing NULL entries at the end.
-                if (any { $_ eq 'output/dev' } @{ $options->{skip} }) {
-                    info "skipping output/dev as requested";
-                } else {
-                    print $devtar;
-                }
-
-                if ($options->{mode} eq 'fakechroot') {
-                    # By default, FAKECHROOT_EXCLUDE_PATH includes /proc and
-                    # /sys which means that the resulting tarball will contain
-                    # the permission and ownership information of /proc and
-                    # /sys from the outside, which we want to avoid.
+            } elsif ($options->{mode} eq 'fakechroot') {
+                # By default, FAKECHROOT_EXCLUDE_PATH includes /proc and /sys
+                # which means that the resulting tarball will contain the
+                # permission and ownership information of /proc and /sys from
+                # the outside, which we want to avoid.
                 ## no critic (Variables::RequireLocalizedPunctuationVars)
                 $ENV{FAKECHROOT_EXCLUDE_PATH} = "/dev";
-                    # Fakechroot requires tar to run inside the chroot or
-                    # otherwise absolute symlinks will include the path to the
-                    # root directory
+                # Fakechroot requires tar to run inside the chroot or otherwise
+                # absolute symlinks will include the path to the root directory
                 0 == system('chroot', $options->{root}, 'tar',
                     @taropts, '-C', '/', '.')
                   or error "tar failed: $?";
-                } elsif (any { $_ eq $options->{mode} } ('root', 'chrootless'))
-                {
-                    # If the chroot directory is not owned by the root user,
-                    # then we assume that no measure was taken to fake root
-                    # permissions. Since the final tarball should contain
-                    # entries with root ownership, we instruct tar to do so.
+            } elsif (any { $_ eq $options->{mode} } ('root', 'chrootless')) {
+                # If the chroot directory is not owned by the root user, then
+                # we assume that no measure was taken to fake root permissions.
+                # Since the final tarball should contain entries with root
+                # ownership, we instruct tar to do so.
                 my @owneropts = ();
                 if ((stat $options->{root})[4] != 0) {
                     push @owneropts, '--owner=0', '--group=0',
@@ -6136,6 +6068,16 @@ sub main() {
         }
 
         exit 0;
+    };
+
+    my $pid;
+    if ($options->{mode} eq 'unshare') {
+        $pid = get_unshare_cmd($worker, \@idmap);
+    } elsif (any { $_ eq $options->{mode} }
+        ('root', 'fakechroot', 'chrootless')) {
+        $pid = fork() // error "fork() failed: $!";
+        if ($pid == 0) {
+            $worker->();
         }
     } else {
         error "unknown mode: $options->{mode}";
@@ -7525,7 +7467,7 @@ translated manual packages (but not the untranslated ones), and documentation
 Create a bootable USB Stick that boots into a full Debian desktop:
 
     $ mmdebstrap --aptopt='Apt::Install-Recommends "true"' --customize-hook \
-        'chroot "$1" adduser --gecos user --disabled-password user' \
+        'chroot "$1" adduser --comment user --disabled-password user' \
         --customize-hook='echo 'user:live' | chroot "$1" chpasswd' \
         --customize-hook='echo host > "$1/etc/hostname"' \
         --customize-hook='echo "127.0.0.1 localhost host" > "$1/etc/hosts"' \