Upgrade to CPAN-1.88_54.

p4raw-id: //depot/perl@29020

3 files changed, 403 insertions, 80 deletions

diff --git a/lib/CPAN.pm b/lib/CPAN.pm
index 1864e0f348..eeb6dbbd38 100644
--- a/lib/CPAN.pm
+++ b/lib/CPAN.pm
@@ -1,7 +1,7 @@
 # -*- Mode: cperl; coding: utf-8; cperl-indent-level: 4 -*-
 use strict;
 package CPAN;
-$CPAN::VERSION = '1.88_53';
+$CPAN::VERSION = '1.88_54';
 $CPAN::VERSION = eval $CPAN::VERSION;
 
 use CPAN::HandleConfig;
@@ -337,6 +337,28 @@ Trying to chdir to "$cwd->[1]" instead.
     }
 }
 
+# CPAN::_yaml_loadfile
+sub _yaml_loadfile {
+    my($self,$local_file) = @_;
+    my $yaml_module = $CPAN::Config->{yaml_module} || "YAML";
+    if ($CPAN::META->has_inst($yaml_module)) {
+        my $code = UNIVERSAL::can($yaml_module, "LoadFile");
+        my $yaml;
+        eval { $yaml = $code->($local_file); };
+        if ($@) {
+            $CPAN::Frontend->mydie("Alert: While trying to parse YAML file\n".
+                                   "  $local_file\n".
+                                   "with $yaml_module the following error was encountered:\n".
+                                   "  $@\n"
+                                  );
+        }
+        return $yaml;
+    } else {
+        $CPAN::Frontend->mywarn("'$yaml_module' not installed, cannot parse '$local_file'\n");
+    }
+    return +{};
+}
+
 package CPAN::CacheMgr;
 use strict;
 @CPAN::CacheMgr::ISA = qw(CPAN::InfoObj CPAN);
@@ -2491,7 +2513,6 @@ to find objects with matching identifiers.
     }
     for my $obj (@qcopy) {
         $obj->color_cmd_tmps(0,0);
-        delete $obj->{incommandcolor};
     }
 }
 
@@ -3711,7 +3732,8 @@ sub rd_authindex {
     local($_);
     push @lines, split /\012/ while <FH>;
     my $i = 0;
-    my $modulus = int(@lines/75) || 1;
+    my $modulus = int($#lines/75) || 1;
+    CPAN->debug(sprintf "modulus[%d]lines[%s]", $modulus, scalar @lines) if $CPAN::DEBUG;
     foreach (@lines) {
 	my($userid,$fullname,$email) =
 	    m/alias\s+(\S+)\s+\"([^\"\<]+)\s+\<([^\>]+)\>\"/;
@@ -3836,7 +3858,7 @@ happen.\a
     CPAN->debug("secondtime[$secondtime]") if $CPAN::DEBUG;
     my(%exists);
     my $i = 0;
-    my $modulus = int(@lines/75) || 1;
+    my $modulus = int($#lines/75) || 1;
     foreach (@lines) {
         # before 1.56 we split into 3 and discarded the rest. From
         # 1.57 we assign remaining text to $comment thus allowing to
@@ -3975,7 +3997,7 @@ sub rd_modlist {
     Carp::confess($@) if $@;
     return if $CPAN::Signal;
     my $i = 0;
-    my $until = keys %$ret;
+    my $until = keys(%$ret) - 1;
     my $modulus = int($until/75) || 1;
     CPAN->debug(sprintf "until[%d]", $until) if $CPAN::DEBUG;
     for (keys %$ret) {
@@ -4492,12 +4514,7 @@ sub fast_yaml {
                                 $local_wanted)) {
         $CPAN::Frontend->mydie("Giving up on downloading yaml file '$local_wanted'\n");
     }
-    if ($CPAN::META->has_inst("YAML")) {
-        my $yaml = YAML::LoadFile($local_file);
-        return $yaml;
-    } else {
-        $CPAN::Frontend->mydie("Yaml not installed, cannot parse '$local_file'\n");
-    }
+    my $yaml = CPAN->_yaml_loadfile($local_file);
 }
 
 #-> sub CPAN::Distribution::pretty_id
@@ -5534,13 +5551,21 @@ is part of the perl-%s distribution. To install that, you need to run
 #	$switch = "-MExtUtils::MakeMaker ".
 #	    "-Mops=:default,:filesys_read,:filesys_open,require,chdir"
 #	    if $] > 5.00310;
+        my $makepl_arg = $self->make_x_arg("pl");
 	$system = sprintf("%s%s Makefile.PL%s",
                           $perl,
                           $switch ? " $switch" : "",
-                          $CPAN::Config->{makepl_arg} ? " $CPAN::Config->{makepl_arg}" : "",
+                          $makepl_arg ? " $makepl_arg" : "",
                          );
     }
-    unless (exists $self->{writemakefile}) {
+    local %ENV = %ENV;
+    if (my $env = $self->prefs->{pl}{env}) {
+        for my $e (keys %$env) {
+            $ENV{$e} = $env->{$e};
+        }
+    }
+    if (exists $self->{writemakefile}) {
+    } else {
 	local($SIG{ALRM}) = sub { die "inactivity_timeout reached\n" };
 	my($ret,$pid);
 	$@ = "";
@@ -5594,13 +5619,17 @@ is part of the perl-%s distribution. To install that, you need to run
                 return;
             }
 	} else {
-	  $ret = system($system);
-	  if ($ret != 0) {
-	    $self->{writemakefile} = CPAN::Distrostatus
-                ->new("NO '$system' returned status $ret");
-            $CPAN::Frontend->mywarn("Warning: No success on command[$system]\n");
-	    return;
-	  }
+            if (my $expect = $self->prefs->{pl}{expect}) {
+                $ret = $self->run_via_expect($system,$expect);
+            } else {
+                $ret = system($system);
+            }
+            if ($ret != 0) {
+                $self->{writemakefile} = CPAN::Distrostatus
+                    ->new("NO '$system' returned status $ret");
+                $CPAN::Frontend->mywarn("Warning: No success on command[$system]\n");
+                return;
+            }
 	}
 	if (-f "Makefile" || -f "Build") {
 	  $self->{writemakefile} = CPAN::Distrostatus->new("YES");
@@ -5625,6 +5654,10 @@ is part of the perl-%s distribution. To install that, you need to run
             return 1 if $self->follow_prereqs(@prereq); # signal success to the queuerunner
         }
     }
+    if ($CPAN::Signal){
+      delete $self->{force_update};
+      return;
+    }
     if ($self->{modulebuild}) {
         unless (-f "Build") {
             my $cwd = Cwd::cwd;
@@ -5636,6 +5669,19 @@ is part of the perl-%s distribution. To install that, you need to run
     } else {
         $system = join " ", $self->_make_command(), $CPAN::Config->{make_arg};
     }
+    my $make_arg = $self->make_x_arg("make");
+    $system = sprintf("%s%s",
+                      $system,
+                      $make_arg ? " $make_arg" : "",
+                     );
+    if (my $env = $self->prefs->{make}{env}) { # overriding the local
+                                               # ENV of PL, not the
+                                               # outer ENV, but
+                                               # unlikely to be a risk
+        for my $e (keys %$env) {
+            $ENV{$e} = $env->{$e};
+        }
+    }
     if (system($system) == 0) {
 	 $CPAN::Frontend->myprint("  $system -- OK\n");
 	 $self->{make} = CPAN::Distrostatus->new("YES");
@@ -5646,19 +5692,170 @@ is part of the perl-%s distribution. To install that, you need to run
     }
 }
 
+# CPAN::Distribution::run_via_expect
+sub run_via_expect {
+    my($self,$system,$expect) = @_;
+    CPAN->debug("system[$system]expect[$expect]") if $CPAN::DEBUG;
+    if ($CPAN::META->has_inst("Expect")) {
+        my $expo = Expect->new;
+        $expo->spawn($system);
+      EXPECT: for (my $i = 0; $i < $#$expect; $i+=2) {
+            my $regex = eval "qr{$expect->[$i]}";
+            my $send = $expect->[$i+1];
+            $expo->expect(10,
+                          [ eof => sub {
+                                my $but = $expo->clear_accum;
+                                $CPAN::Frontend->mywarn("EOF (maybe harmless) system[$system]
+expected[$regex]\nbut[$but]\n\n");
+                                last EXPECT;
+                            } ],
+                          [ timeout => sub {
+                                my $but = $expo->clear_accum;
+                                $CPAN::Frontend->mydie("TIMEOUT system[$system]
+expected[$regex]\nbut[$but]\n\n");
+                            } ],
+                          -re => $regex);
+            $expo->send($send);
+        }
+        $expo->soft_close;
+        return $expo->exitstatus();
+    } else {
+        $CPAN::Frontend->mywarn("Expect not installed, falling back to system()\n");
+        return system($system);
+    }
+}
+
+# CPAN::Distribution::_find_prefs
+sub _find_prefs {
+    my($self,$distro) = @_;
+    my $distroid = $distro->pretty_id;
+    CPAN->debug("distroid[$distroid]") if $CPAN::DEBUG;
+    my $prefs_dir = $CPAN::Config->{prefs_dir};
+    eval { File::Path::mkpath($prefs_dir); };
+    if ($@) {
+        $CPAN::Frontend->mydie("Cannot create directory $prefs_dir");
+    }
+    my $yaml_module = $CPAN::Config->{yaml_module} || "YAML";
+    if ($CPAN::META->has_inst($yaml_module)) {
+        my $dh = DirHandle->new($prefs_dir)
+            or die Carp::croak("Couldn't open '$prefs_dir': $!");
+      DIRENT: for (sort $dh->read) {
+            next if $_ eq "." || $_ eq "..";
+            next unless /\.yml$/;
+            my $abs = File::Spec->catfile($prefs_dir, $_);
+            CPAN->debug("abs[$abs]") if $CPAN::DEBUG;
+            if (-f $abs) {
+                my $yaml = CPAN->_yaml_loadfile($abs);
+                my $ok = 1;
+                my $match = $yaml->{match} or
+                    $CPAN::Frontend->mydie("Nonconforming YAML file '$abs': ".
+                                           "missing attribut 'match'. Please ".
+                                           "remove, cannot continue.");
+                for my $sub_attribute (keys %$match) {
+                    my $qr = eval "qr{$yaml->{match}{$sub_attribute}}";
+                    if ($sub_attribute eq "module") {
+                        my $okm = 0;
+                        my @modules = $distro->containsmods;
+                        for my $module (@modules) {
+                            $okm ||= $module =~ /$qr/;
+                            last if $okm;
+                        }
+                        $ok &&= $okm;
+                    } elsif ($sub_attribute eq "distribution") {
+                        my $okd = $distroid =~ /$qr/;
+                        $ok &&= $okd;
+                    } else {
+                        $CPAN::Frontend->mydie("Nonconforming YAML file '$abs': ".
+                                               "unknown sub_attribut '$sub_attribute'. ".
+                                               "Please ".
+                                               "remove, cannot continue.");
+                    }
+                }
+                if ($ok) {
+                    return {
+                            prefs => $yaml,
+                            prefs_file => $abs,
+                           };
+                }
+            }
+        }
+    } else {
+        $CPAN::Frontend->mywarn("'$yaml_module' not installed, cannot read prefs '$prefs_dir'\n");
+    }
+    return;
+}
+
+# CPAN::Distribution::prefs
+sub prefs {
+    my($self) = @_;
+    if (exists $self->{prefs}) {
+        return $self->{prefs}; # XXX comment out during debugging
+    }
+    if ($CPAN::Config->{prefs_dir}) {
+        CPAN->debug("prefs_dir[$CPAN::Config->{prefs_dir}]") if $CPAN::DEBUG;
+        my $prefs = $self->_find_prefs($self);
+        if ($prefs) {
+            for my $x (qw(prefs prefs_file)) {
+                $self->{$x} = $prefs->{$x};
+            }
+            my $basename = File::Basename::basename($self->{prefs_file});
+            my $filler1 = "_" x 22;
+            my $filler2 = int(66 - length($basename))/2;
+            $filler2 = 0 if $filler2 < 0;
+            $filler2 = " " x $filler2;
+            $CPAN::Frontend->myprint("
+$filler1 D i s t r o P r e f s $filler1
+$filler2 $basename $filler2
+");
+            $CPAN::Frontend->mysleep(1);
+            return $self->{prefs};
+        }
+    }
+    return +{};
+}
+
+# CPAN::Distribution::make_x_arg
+sub make_x_arg {
+    my($self, $whixh) = @_;
+    my $make_x_arg;
+    my $prefs = $self->prefs;
+    if (
+        $prefs
+        && exists $prefs->{$whixh}
+        && exists $prefs->{$whixh}{args}
+        && $prefs->{$whixh}{args}
+       ) {
+        $make_x_arg = join(" ",
+                           map {CPAN::HandleConfig
+                                 ->safe_quote($_)} @{$prefs->{$whixh}{args}},
+                          );
+    }
+    my $what = sprintf "make%s_arg", $whixh eq "make" ? "" : $whixh;
+    $make_x_arg ||= $CPAN::Config->{$what};
+    return $make_x_arg;
+}
+
+# CPAN::Distribution::_make_command
 sub _make_command {
     my ($self) = @_;
     if ($self) {
         return
-          CPAN::HandleConfig
+            CPAN::HandleConfig
                 ->safe_quote(
-                             $CPAN::Config->{make} || $Config::Config{make} || 'make'
+                             $self->prefs->{cpanconfig}{make}
+                             || $CPAN::Config->{make}
+                             || $Config::Config{make}
+                             || 'make'
                             );
     } else {
         # Old style call, without object. Deprecated
         Carp::confess("CPAN::_make_command() used as function. Don't Do That.");
         return
-          safe_quote(undef, $CPAN::Config->{make} || $Config::Config{make} || 'make');
+          safe_quote(undef,
+                     $self->prefs->{cpanconfig}{make}
+                     || $CPAN::Config->{make}
+                     || $Config::Config{make}
+                     || 'make');
     }
 }
 
@@ -5801,17 +5998,14 @@ sub read_yaml {
     my $yaml = File::Spec->catfile($build_dir,"META.yml");
     $self->debug("yaml[$yaml]") if $CPAN::DEBUG;
     return unless -f $yaml;
-    if ($CPAN::META->has_inst("YAML")) {
-        eval { $self->{yaml_content} = YAML::LoadFile($yaml); };
-        if ($@) {
-            $CPAN::Frontend->mywarn("Error while parsing META.yml: $@");
-            return;
-        }
-        if (not exists $self->{yaml_content}{dynamic_config}
-            or $self->{yaml_content}{dynamic_config}
-           ) {
-            $self->{yaml_content} = undef;
-        }
+    eval { $self->{yaml_content} = CPAN->_yaml_loadfile($yaml); };
+    if ($@) {
+        return; # if we die, then we cannot read our own META.yml
+    }
+    if (not exists $self->{yaml_content}{dynamic_config}
+        or $self->{yaml_content}{dynamic_config}
+       ) {
+        $self->{yaml_content} = undef;
     }
     $self->debug(sprintf "yaml_content[%s]", $self->{yaml_content} || "UNDEF")
         if $CPAN::DEBUG;
@@ -6023,9 +6217,18 @@ sub test {
     } else {
         $system = join " ", $self->_make_command(), "test";
     }
-    my $tests_ok;
-    if ( $CPAN::Config->{test_report} && 
-         $CPAN::META->has_inst("CPAN::Reporter") ) {
+    my($tests_ok);
+    local %ENV = %ENV;
+    if (my $env = $self->prefs->{test}{env}) {
+        for my $e (keys %$env) {
+            $ENV{$e} = $env->{$e};
+        }
+    }
+    my $expect = $self->prefs->{test}{expect};
+    if ($expect && @$expect) {
+        $tests_ok = $self->run_via_expect($system,$expect) == 0;
+    } elsif ( $CPAN::Config->{test_report} && 
+              $CPAN::META->has_inst("CPAN::Reporter") ) {
         $tests_ok = CPAN::Reporter::test($self, $system);
     } else {
         $tests_ok = system($system) == 0;
@@ -6035,11 +6238,14 @@ sub test {
             my @prereq;
             for my $m (keys %{$self->{sponsored_mods}}) {
                 my $m_obj = CPAN::Shell->expand("Module",$m);
-                if (!$m_obj->distribution->{make_test}
-                    ||
-                    $m_obj->distribution->{make_test}->failed){
-                    #$m_obj->dump;
-                    push @prereq, $m;
+                my $d_obj = $m_obj->distribution;
+                if ($d_obj) {
+                    if (!$d_obj->{make_test}
+                        ||
+                        $d_obj->{make_test}->failed){
+                        #$m_obj->dump;
+                        push @prereq, $m;
+                    }
                 }
             }
             if (@prereq){
@@ -6220,8 +6426,10 @@ sub install {
                           $CPAN::Config->{mbuild_install_arg},
                          );
     } else {
-        my($make_install_make_command) = $CPAN::Config->{make_install_make_command} ||
-            $self->_make_command();
+        my($make_install_make_command) =
+            $self->prefs->{cpanconfig}{make_install_make_command}
+                || $CPAN::Config->{make_install_make_command}
+                    || $self->_make_command();
         $system = sprintf("%s install %s",
                           $make_install_make_command,
                           $CPAN::Config->{make_install_arg},
@@ -6229,14 +6437,16 @@ sub install {
     }
 
     my($stderr) = $^O eq "MSWin32" ? "" : " 2>&1 ";
-    $CPAN::Config->{build_requires_install_policy}||="ask/yes";
+    my $brip = $self->prefs->{cpanconfig}{build_requires_install_policy};
+    $brip ||= $CPAN::Config->{build_requires_install_policy};
+    $brip ||="ask/yes";
     my $id = $self->id;
     my $reqtype = $self->{reqtype} ||= "c"; # in doubt it was a command
     my $want_install = "yes";
     if ($reqtype eq "b") {
-        if ($CPAN::Config->{build_requires_install_policy} eq "no") {
+        if ($brip eq "no") {
             $want_install = "no";
-        } elsif ($CPAN::Config->{build_requires_install_policy} =~ m|^ask/(.+)|) {
+        } elsif ($brip =~ m|^ask/(.+)|) {
             my $default = $1;
             $default = "yes" unless $default =~ /^(y|n)/i;
             $want_install =
@@ -6269,12 +6479,16 @@ sub install {
     } else {
         $self->{install} = CPAN::Distrostatus->new("NO");
         $CPAN::Frontend->mywarn("  $system -- NOT OK\n");
+        my $mimc =
+            $self->prefs->{cpanconfig}{make_install_make_command} ||
+                $CPAN::Config->{make_install_make_command};
         if (
             $makeout =~ /permission/s
             && $> > 0
             && (
-                ! $CPAN::Config->{make_install_make_command}
-                || $CPAN::Config->{make_install_make_command} eq $CPAN::Config->{make}
+                ! $mimc
+                || $mimc eq ($self->prefs->{cpanconfig}{make}
+                             || $CPAN::Config->{make})
                )
            ) {
             $CPAN::Frontend->myprint(
@@ -7386,23 +7600,30 @@ Batch mode:
 
   use CPAN;
 
-  # modules:
+  # Modules:
+
+  cpan> install Acme::Meta                       # in the shell
+
+  CPAN::Shell->install("Acme::Meta");            # in perl
+
+  # Distributions:
+
+  cpan> install NWCLARK/Acme-Meta-0.02.tar.gz    # in the shell
+
+  CPAN::Shell->
+    install("NWCLARK/Acme-Meta-0.02.tar.gz");    # in perl
+
+  # module objects:
 
-  $mod = "Acme::Meta";
-  install $mod;
-  CPAN::Shell->install($mod);                    # same thing
-  CPAN::Shell->expandany($mod)->install;         # same thing
-  CPAN::Shell->expand("Module",$mod)->install;   # same thing
-  CPAN::Shell->expand("Module",$mod)
-    ->distribution->install;                     # same thing
+  $mo = CPAN::Shell->expandany($mod);
+  $mo = CPAN::Shell->expand("Module",$mod);      # same thing
 
-  # distributions:
+  # distribution objects:
 
-  $distro = "NWCLARK/Acme-Meta-0.01.tar.gz";
-  install $distro;                                # same thing
-  CPAN::Shell->install($distro);                  # same thing
-  CPAN::Shell->expandany($distro)->install;       # same thing
-  CPAN::Shell->expand("Distribution",$distro)->install; # same thing
+  $do = CPAN::Shell->expand("Module",$mod)->distribution;
+  $do = CPAN::Shell->expandany($distro);         # same thing
+  $do = CPAN::Shell->expand("Distribution",
+                            $distro);            # same thing
 
 =head1 STATUS
 
@@ -7732,8 +7953,7 @@ functionalities that are available in the shell.
 
     # install my favorite programs if necessary:
     for $mod (qw(Net::FTP Digest::SHA Data::Dumper)){
-        my $obj = CPAN::Shell->expand('Module',$mod);
-        $obj->install;
+        CPAN::Shell->install($mod);
     }
 
     # list all modules on my disk that have no VERSION number
@@ -7935,6 +8155,10 @@ any case and if this fails, the install will be canceled. The
 cancellation can be avoided by letting C<force> run the C<install> for
 you.
 
+This install method has only the power to install the distribution if
+there are no dependencies in the way. To install an object and all of
+its dependencies, use CPAN::Shell->install.
+
 Note that install() gives no meaningful return value. See uptodate().
 
 =item CPAN::Distribution::isa_perl()
@@ -7965,6 +8189,19 @@ isn't available, it converts it to plain text with external
 command html2text and runs it through the pager specified
 in C<$CPAN::Config->{pager}>
 
+=item CPAN::Distribution::prefs()
+
+Returns the hash reference from the first matching YAML file that the
+user has deposited in the C<prefs_dir/> directory. The first
+succeeding match wins. The files in the C<prefs_dir/> are processed
+alphabetically and the canonical distroname (e.g.
+AUTHOR/Foo-Bar-3.14.tar.gz) is matched against the regular expressions
+stored in the $root->{match}{distribution} attribute value.
+Additionally all module names contained in a distribution are matched
+agains the regular expressions in the $root->{match}{module} attribute
+value. The two match values are ANDed together. Each of the two
+attributes are optional.
+
 =item CPAN::Distribution::prereq_pm()
 
 Returns the hash reference that has been announced by a distribution
@@ -8428,6 +8665,7 @@ defined:
   prerequisites_policy
                      what to do if you are missing module prerequisites
                      ('follow' automatically, 'ask' me, or 'ignore')
+  prefs_dir          local directory to store per-distro build options
   proxy_user         username for accessing an authenticating proxy
   proxy_pass         password for accessing an authenticating proxy
   scan_cache	     controls scanning of cache ('atstart' or 'never')
@@ -8443,6 +8681,7 @@ defined:
   username           your username if you CPAN server wants one
   wait_list          arrayref to a wait server to try (See CPAN::WAIT)
   wget               path to external prg
+  yaml_module        which module to use to read/write YAML files
 
 You can set and query each of these options interactively in the cpan
 shell with the command set defined within the C<o conf> command:
@@ -8534,6 +8773,36 @@ site will be tried another time. This means that if you want to disallow
 a site for the next transfer, it must be explicitly removed from
 urllist.
 
+=head2 prefs_dir for avoiding interactive questions (ALPHA)
+
+(B<Note:> This feature has been introduced in CPAN.pm 1.8854 and is
+still considered experimental and may still be changed)
+
+The files in the directory specified in C<prefs_dir> are YAML files
+that specify how CPAN.pm shall treat distributions that deviate from
+the normal non-interactive model of building and installing CPAN
+modules.
+
+Some modules try to get some data from the user interactively thus
+disturbing the installation of large bundles like Phalanx100 or
+modules like Plagger.
+
+CPAN.pm can use YAML files to either pass additional arguments to one
+of the four commands, set environment variables or instantiate an
+Expect object that reads from the console, waits for some regular
+expression and enters some answer. Needless to say that for the latter
+option Expect.pm needs to be installed.
+
+CPAN.pm comes with a couple of such YAML files. The structure is
+currently not documented. Please see the distroprefs directory of the
+CPAN distribution for examples and follow the README in there.
+
+Please note that setting the environment variable PERL_MM_USE_DEFAULT
+to a true value can also get you a long way if you want to always pick
+the default answers. But this only works if the author of apackage
+used the prompt function provided by ExtUtils::MakeMaker and if the
+defaults are OK for you.
+
 =head1 SECURITY
 
 There's no strong security layer in CPAN.pm. CPAN.pm helps you to
diff --git a/lib/CPAN/FirstTime.pm b/lib/CPAN/FirstTime.pm
index 692f6c9cd5..f04985b0d1 100644
--- a/lib/CPAN/FirstTime.pm
+++ b/lib/CPAN/FirstTime.pm
@@ -19,7 +19,7 @@ use File::Basename ();
 use File::Path ();
 use File::Spec;
 use vars qw($VERSION $urllist);
-$VERSION = sprintf "%.6f", substr(q$Rev: 924 $,4)/1000000 + 5.4;
+$VERSION = sprintf "%.6f", substr(q$Rev: 1012 $,4)/1000000 + 5.4;
 
 =head1 NAME
 
@@ -144,7 +144,7 @@ sub init {
       }
     }
 
-    if (!$matcher or 'cpan_home keep_source_where build_dir' =~ /$matcher/){
+    if (!$matcher or 'cpan_home keep_source_where build_dir prefs_dir' =~ /$matcher/){
         $CPAN::Frontend->myprint($prompts{config_intro});
 
         if (!$matcher or 'cpan_home' =~ /$matcher/) {
@@ -165,6 +165,7 @@ Shall we use it as the general CPAN build and cache directory?
             }
 
             $default = $cpan_home;
+            my $loop = 0;
             while ($ans = prompt("CPAN build and cache directory?",$default)) {
                 unless (File::Spec->file_name_is_absolute($ans)) {
                     require Cwd;
@@ -187,6 +188,9 @@ Shall we use it as the general CPAN build and cache directory?
                 } else {
                     $CPAN::Frontend->mywarn("Couldn't find directory $ans\n".
                                             "or directory is not writable. Please retry.\n");
+                    if (++$loop > 5) {
+                        $CPAN::Frontend->mydie("Giving up");
+                    }
                 }
             }
             $CPAN::Config->{cpan_home} = $ans;
@@ -205,6 +209,13 @@ Shall we use it as the general CPAN build and cache directory?
                            $matcher
                           );
         }
+
+        if (!$matcher or 'prefs_dir' =~ /$matcher/) {
+            my_dflt_prompt("prefs_dir",
+                           File::Spec->catdir($CPAN::Config->{cpan_home},"prefs"),
+                           $matcher
+                          );
+        }
     }
 
     #
@@ -212,21 +223,16 @@ Shall we use it as the general CPAN build and cache directory?
     #
 
     if (!$matcher or 'build_cache' =~ /$matcher/){
-        $CPAN::Frontend->myprint($prompts{build_cache_intro});
-
         # large enough to build large dists like Tk
         my_dflt_prompt(build_cache => 100, $matcher);
     }
 
     if (!$matcher or 'index_expire' =~ /$matcher/) {
-        $CPAN::Frontend->myprint($prompts{index_expire_intro});
-
         my_dflt_prompt(index_expire => 1, $matcher);
     }
 
     if (!$matcher or 'scan_cache' =~ /$matcher/){
         $CPAN::Frontend->myprint($prompts{scan_cache_intro});
-
         my_prompt_loop(scan_cache => 'atstart', $matcher, 'atstart|never');
     }
 
@@ -278,6 +284,13 @@ Shall we use it as the general CPAN build and cache directory?
     }
 
     #
+    #= YAML vs. YAML::Syck
+    #
+    if (!$matcher or "yaml_module" =~ /$matcher/) {
+        my_dflt_prompt(yaml_module => "YAML", $matcher);
+    }
+
+    #
     #= External programs
     #
 
@@ -370,8 +383,6 @@ Shall we use it as the general CPAN build and cache directory?
     }
 
     if (!$matcher or 'makepl_arg make_arg' =~ /$matcher/){
-        $CPAN::Frontend->myprint($prompts{makepl_arg_intro});
-
         my_dflt_prompt(makepl_arg => "", $matcher);
         my_dflt_prompt(make_arg => "", $matcher);
     }
@@ -388,10 +399,7 @@ Shall we use it as the general CPAN build and cache directory?
 		   $matcher);
 
     if (!$matcher or 'mbuildpl_arg mbuild_arg' =~ /$matcher/){
-        $CPAN::Frontend->myprint($prompts{mbuildpl_arg_intro});
-
         my_dflt_prompt(mbuildpl_arg => "", $matcher);
-
         my_dflt_prompt(mbuild_arg => "", $matcher);
     }
 
@@ -574,6 +582,9 @@ sub my_dflt_prompt {
 
     $DB::single = 1;
     if (!$m || $item =~ /$m/) {
+        if (my $intro = $prompts{$item . "_intro"}) {
+            $CPAN::Frontend->myprint($intro);
+        }
 	$CPAN::Config->{$item} = prompt($prompts{$item}, $default);
     } else {
 	$CPAN::Config->{$item} = $default;
@@ -845,6 +856,7 @@ put them on one line, separated by blanks, hyphenated ranges allowed
 sub bring_your_own {
     my %seen = map (($_ => 1), @$urllist);
     my($ans,@urls);
+    my $eacnt = 0; # empty answers
     do {
 	my $prompt = "Enter another URL or RETURN to quit:";
 	unless (%seen) {
@@ -871,6 +883,13 @@ later if you\'re sure it\'s right.\n},
                                    || "configuration file",
                                   ));
             }
+        } else {
+            if (++$eacnt >= 5) {
+                $CPAN::Frontend->
+                    mywarn("Giving up.\n");
+                $CPAN::Frontend->mysleep(5);
+                return;
+            }
         }
     } while $ans || !%seen;
 
@@ -929,7 +948,7 @@ config_intro => qq{
 The following questions are intended to help you with the
 configuration. The CPAN module needs a directory of its own to cache
 important index files and maybe keep a temporary mirror of CPAN files.
-This may be a site-wide directory or a personal directory.
+This may be a site-wide or a personal directory.
 
 },
 
@@ -961,6 +980,24 @@ build_dir =>
 
 "Directory where the build process takes place?",
 
+prefs_dir_intro => qq{
+
+CPAN.pm can store customized build environments based on regular
+expressions for distribution names. These are YAML files where the
+default options for CPAN.pm and the environment can be overridden and
+dialog sequences can be stored that can later be executed by an
+Expect.pm object. The CPAN.pm distribution comes with some prefab YAML
+files that cover sample distributions that can be used as blueprints
+to store one own prefs. Please check out the distroprefs/ directory of
+the CPAN.pm distribution to get a quick start into the prefs system.
+
+},
+
+prefs_dir =>
+
+"Directory where to store default options/environment/dialogs for
+building modules that need some customization?",
+
 scan_cache_intro => qq{
 
 By default, each time the CPAN module is started, cache scanning is
@@ -1344,6 +1381,18 @@ build_requires_install_policy =>
 qq{Policy on installing 'build_requires' modules (yes, no, ask/yes,
 ask/no)?},
 
+yaml_module_intro => qq{
+
+At the time of this writing there are two competing YAML modules,
+YAML.pm and YAML::Syck. The latter is faster but needs a C compiler
+installed on your system. There may be more alternative YAML
+conforming modules but at the time of writing a potential third
+player, YAML::Tiny, is not yet sufficiently similar to the other two.
+
+},
+
+yaml_module => qq{Which YAML implementation would you prefer?},
+
 );
 
 die "Coding error in \@prompts declaration.  Odd number of elements, above"
diff --git a/lib/CPAN/HandleConfig.pm b/lib/CPAN/HandleConfig.pm
index 557aac5fed..b6af22b7c2 100644
--- a/lib/CPAN/HandleConfig.pm
+++ b/lib/CPAN/HandleConfig.pm
@@ -2,7 +2,7 @@ package CPAN::HandleConfig;
 use strict;
 use vars qw(%can %keys $VERSION);
 
-$VERSION = sprintf "%.6f", substr(q$Rev: 984 $,4)/1000000 + 5.4;
+$VERSION = sprintf "%.6f", substr(q$Rev: 987 $,4)/1000000 + 5.4;
 
 %can = (
         commit   => "Commit changes to disk",
@@ -11,6 +11,9 @@ $VERSION = sprintf "%.6f", substr(q$Rev: 984 $,4)/1000000 + 5.4;
         init     => "Interactive setting of all options",
 );
 
+# Q: where is the "How do I add a new config option" HOWTO?
+# A1: svn diff -r 757:758 # where dagolden added test_report
+# A2: svn diff -r 985:986 # where andk added yaml_module
 %keys = map { $_ => undef } (
                              #  allow_unauthenticated ?? some day...
                              "build_cache",
@@ -58,6 +61,7 @@ $VERSION = sprintf "%.6f", substr(q$Rev: 984 $,4)/1000000 + 5.4;
                              "password",
                              "prefer_installer",
                              "prerequisites_policy",
+                             "prefs_dir",
                              "proxy_pass",
                              "proxy_user",
                              "scan_cache",
@@ -72,6 +76,7 @@ $VERSION = sprintf "%.6f", substr(q$Rev: 984 $,4)/1000000 + 5.4;
                              "username",
                              "wait_list",
                              "wget",
+                             "yaml_module",
                             );
 if ($^O eq "MSWin32") {
     for my $k (qw(
@@ -581,7 +586,7 @@ package
 
 use strict;
 use vars qw($AUTOLOAD $VERSION);
-$VERSION = sprintf "%.2f", substr(q$Rev: 984 $,4)/100;
+$VERSION = sprintf "%.2f", substr(q$Rev: 987 $,4)/100;
 
 # formerly CPAN::HandleConfig was known as CPAN::Config
 sub AUTOLOAD {