* activated 'use warnings' to all modules and adjusted all occurences of

  'use of uninitialized values', a couple of which might still show up
* adjusted all code with respect to passing perlcritic level 4 and 5

git-svn-id: http://svn.openslx.org/svn/openslx/trunk@1207 95ad53e4-c205-0410-b2fa-d234c58c8868

1 files changed, 488 insertions, 319 deletions

diff --git a/installer/OpenSLX/OSSetup/Engine.pm b/installer/OpenSLX/OSSetup/Engine.pm
index 9b69f2b5..53fce7c7 100644
--- a/installer/OpenSLX/OSSetup/Engine.pm
+++ b/installer/OpenSLX/OSSetup/Engine.pm
@@ -13,8 +13,11 @@
 # -----------------------------------------------------------------------------
 package OpenSLX::OSSetup::Engine;
 
-use vars qw(@ISA @EXPORT $VERSION);
-$VERSION = 1.01;		# API-version . implementation-version
+use strict;
+use warnings;
+
+our (@ISA, @EXPORT, $VERSION);
+$VERSION = 1.01;    # API-version . implementation-version
 
 use Exporter;
 @ISA = qw(Exporter);
@@ -23,8 +26,6 @@ use Exporter;
 	%supportedDistros
 );
 
-use strict;
-use Carp;
 use File::Basename;
 use OpenSLX::Basics;
 use OpenSLX::Utils;
@@ -32,40 +33,57 @@ use OpenSLX::Utils;
 use vars qw(%supportedDistros);
 
 %supportedDistros = (
-	'debian-3.1'
-		=> { module => 'Debian_3_1', support => 'clone' },
-	'debian-4.0'
-		=> { module => 'Debian_4_0', support => 'clone' },
-	'fedora-6'
-		=> { module => 'Fedora_6', support => 'clone,install' },
-	'fedora-6_x86_64'
-		=> { module => 'Fedora_6_x86_64', support => 'clone,install' },
-	'gentoo-2005.1'
-		=> { module => 'Gentoo_2005_1', support => 'clone' },
-	'gentoo-2006.1'
-		=> { module => 'Gentoo_2006_1', support => 'clone' },
-	'mandriva-2007.0'
-		=> { module => 'Mandriva_2007_0', support => 'clone' },
-	'suse-9.3'
-		=> { module => 'SUSE_9_3', support => 'clone' },
-	'suse-10.0'
-		=> { module => 'SUSE_10_0', support => 'clone' },
-	'suse-10.0_x86_64'
-		=> { module => 'SUSE_10_0_x86_64', support => 'clone' },
-	'suse-10.1'
-		=> { module => 'SUSE_10_1', support => 'clone,install' },
-	'suse-10.1_x86_64'
-		=> { module => 'SUSE_10_1_x86_64', support => 'clone,install' },
-	'suse-10.2'
-		=> { module => 'SUSE_10_2', support => 'clone,install' },
-	'suse-10.2_x86_64'
-		=> { module => 'SUSE_10_2_x86_64', support => 'clone,install' },
-	'ubuntu-6.06'
-		=> { module => 'Ubuntu_6_06', support => 'clone' },
-	'ubuntu-6.10'
-		=> { module => 'Ubuntu_6_10', support => 'clone' },
-	'ubuntu-7.04'
-		=> { module => 'Ubuntu_7_04', support => 'clone' },
+	'debian-3.1' => {
+		module => 'Debian_3_1',       support => 'clone'
+	},
+	'debian-4.0' => {
+		module => 'Debian_4_0',       support => 'clone'
+	},
+	'fedora-6' => {
+		module => 'Fedora_6',         support => 'clone,install'
+	},
+	'fedora-6_x86_64' => {
+		module => 'Fedora_6_x86_64',  support => 'clone,install'
+	},
+	'gentoo-2005.1' => {
+		module => 'Gentoo_2005_1',    support => 'clone'
+	},
+	'gentoo-2006.1' => {
+		module => 'Gentoo_2006_1',    support => 'clone'
+	},
+	'mandriva-2007.0' => {
+		module => 'Mandriva_2007_0',  support => 'clone'
+	},
+	'suse-9.3' => {
+		module => 'SUSE_9_3',         support => 'clone'
+	},
+	'suse-10.0'	=> {
+		module => 'SUSE_10_0',        support => 'clone'
+	},
+	'suse-10.0_x86_64' => {
+		module => 'SUSE_10_0_x86_64', support => 'clone'
+	},
+	'suse-10.1' => {
+		module => 'SUSE_10_1',        support => 'clone,install'
+	},
+	'suse-10.1_x86_64' => {
+		module => 'SUSE_10_1_x86_64', support => 'clone,install'
+	},
+	'suse-10.2' => {
+		module => 'SUSE_10_2',        support => 'clone,install'
+	},
+	'suse-10.2_x86_64' => {
+		module => 'SUSE_10_2_x86_64', support => 'clone,install'
+	},
+	'ubuntu-6.06' => {
+		module => 'Ubuntu_6_06',      support => 'clone'
+	},
+	'ubuntu-6.10' => {
+		module => 'Ubuntu_6_10',      support => 'clone'
+	},
+	'ubuntu-7.04' => { 
+		module => 'Ubuntu_7_04',      support => 'clone' 
+	},
 );
 
 ################################################################################
@@ -75,8 +93,7 @@ sub new
 {
 	my $class = shift;
 
-	my $self = {
-	};
+	my $self = {};
 
 	return bless $self, $class;
 }
@@ -85,10 +102,11 @@ sub DESTROY
 {
 	my $self = shift;
 
-	if ($self->{'local-http-server-master-pid'} == $$) {
+	my $httpServerPID = $self->{'local-http-server-master-pid'} || '0';
+	if ($httpServerPID == $$) {
 		# we are the master process, so we clean up all the servers that we
 		# have started:
-		while(my ($localURL, $pid) = each %{$self->{'local-http-servers'}}) {
+		while (my ($localURL, $pid) = each %{$self->{'local-http-servers'}}) {
 			vlog(1, _tr("stopping local HTTP-server for URL '%s'.", $localURL));
 			kill TERM => $pid;
 		}
@@ -97,29 +115,34 @@ sub DESTROY
 
 sub initialize
 {
-	my $self = shift;
+	my $self         = shift;
 	my $vendorOSName = shift;
-	my $actionType = shift;
+	my $actionType   = shift;
 
 	if ($vendorOSName !~ m[^([^\-]+\-[^\-]+)(?:\-(.+))?]) {
-		die _tr("Given vendor-OS has unknown format, expected '<name>-<release>[-<selection>]'\n");
+		die _tr(    
+			"Given vendor-OS has unknown format, expected '<name>-<release>[-<selection>]'\n"
+		);
 	}
-	$self->{'vendor-os-name'} = $vendorOSName;
-	$self->{'action-type'} = $actionType;
 	my $distroName = $1;
 	my $selectionName = $2 || 'default';
-	$self->{'distro-name'} = $distroName;
+	$self->{'vendor-os-name'} = $vendorOSName;
+	$self->{'action-type'}    = $actionType;
+	$self->{'distro-name'}    = $distroName;
 	$self->{'selection-name'} = $selectionName;
+	$self->{'clone-source'}   = '';
 	if (!exists $supportedDistros{lc($distroName)}) {
 		print _tr("Sorry, distro '%s' is unsupported.\n", $distroName);
 		print _tr("List of supported distros:\n\t");
-		print join("\n\t", sort keys %supportedDistros)."\n";
+		print join("\n\t", sort keys %supportedDistros) . "\n";
 		exit 1;
 	}
 	my $support = $supportedDistros{lc($distroName)}->{support};
 	if ($actionType eq 'install' && $support !~ m[install]i) {
-		print _tr("Sorry, distro '%s' can not be installed, only cloned.\n",
-				  $distroName);
+		print _tr(
+			"Sorry, distro '%s' can not be installed, only cloned.\n", 
+			$distroName
+		);
 		exit 1;
 	}
 
@@ -130,7 +153,8 @@ sub initialize
 		# distro's for which there is no specific distro-module yet
 		# (like for example for Gentoo):
 		$distroClass = "Any_Clone";
-	} else {
+	}
+	else {
 		$distroClass = $supportedDistros{lc($distroName)}->{module};
 	}
 	my $distro = instantiateClass("OpenSLX::OSSetup::Distro::$distroClass");
@@ -142,30 +166,39 @@ sub initialize
 		my $sharedDistroInfoDir 
 			= "$openslxConfig{'base-path'}/share/distro-info/$distro->{'base-name'}";
 		if (!-d $sharedDistroInfoDir) {
-			die _tr("unable to find shared distro-info in '%s'\n", 
-					$sharedDistroInfoDir);
+			die _tr(
+				"unable to find shared distro-info in '%s'\n",
+				$sharedDistroInfoDir
+			);
 		}
 		$self->{'shared-distro-info-dir'} = $sharedDistroInfoDir;
-		my $configDistroInfoDir 
-			= "$openslxConfig{'config-path'}/distro-info/$distro->{'base-name'}";
+		my $configDistroInfoDir =
+			"$openslxConfig{'config-path'}/distro-info/$distro->{'base-name'}";
 		if (!-d $configDistroInfoDir) {
-			die _tr("unable to find configurable distro-info in '%s'\n", 
-					$configDistroInfoDir);
+			die _tr(
+				"unable to find configurable distro-info in '%s'\n",
+				$configDistroInfoDir
+			);
 		}
 		$self->{'config-distro-info-dir'} = $configDistroInfoDir;
 		$self->readDistroInfo();
 	}
 
 	if (!$self->{'action-type'} eq 'install'
-	&& !exists $self->{'distro-info'}->{'selection'}->{$selectionName}) {
-		die _tr("selection '%s' is unknown to distro '%s'\n",
-				$selectionName, $distro->{'base-name'})
-			."These selections are available:\n\t"
-			.join("\n\t", keys %{$self->{'distro-info'}->{'selection'}})
-			."\n";
+		&& !exists $self->{'distro-info'}->{'selection'}->{$selectionName})
+	{
+		die(
+			_tr(
+				"selection '%s' is unknown to distro '%s'\n",
+				$selectionName, $distro->{'base-name'}
+			)
+			. _tr("These selections are available:\n\t")
+			. join("\n\t", keys %{$self->{'distro-info'}->{'selection'}})
+			. "\n"
+		);
 	}
 
-	$self->{'vendor-os-path'}
+	$self->{'vendor-os-path'} 
 		= "$openslxConfig{'private-path'}/stage1/$self->{'vendor-os-name'}";
 	vlog(1, "vendor-OS path is '$self->{'vendor-os-path'}'");
 
@@ -181,7 +214,8 @@ sub installVendorOS
 
 	my $installInfoFile = "$self->{'vendor-os-path'}/.openslx-install-info";
 	if (-e $installInfoFile) {
-		die _tr("vendor-OS '%s' already exists, giving up!\n", $self->{'vendor-os-path'});
+		die _tr("vendor-OS '%s' already exists, giving up!\n",
+			$self->{'vendor-os-path'});
 	}
 	$self->createVendorOSPath();
 
@@ -190,33 +224,43 @@ sub installVendorOS
 	my $baseSystemFile = "$self->{'vendor-os-path'}/.openslx-base-system";
 	if (-e $baseSystemFile) {
 		vlog(0, _tr("found existing base system, continuing...\n"));
-	} else {
+	}
+	else {
 		# basic setup, stage1a-c:
-	 	$self->setupStage1A();
-	 	callInSubprocess( sub {
-	 		# some tasks that involve a chrooted environment:
-			$self->changePersonalityIfNeeded();
-	 		$self->setupStage1B();
-	 		$self->setupStage1C();
-	 	});
-	 	$self->stage1C_cleanupBasicVendorOS();
+		$self->setupStage1A();
+		callInSubprocess(
+			sub {
+				# some tasks that involve a chrooted environment:
+				$self->changePersonalityIfNeeded();
+				$self->setupStage1B();
+				$self->setupStage1C();
+			}
+		);
+		$self->stage1C_cleanupBasicVendorOS();
+		# just touch the file, in order to indicate a basic system:
 		slxsystem("touch $baseSystemFile");
-			# just touch the file, in order to indicate a basic system
 	}
-	callInSubprocess( sub {
-		# another task that involves a chrooted environment:
-		$self->changePersonalityIfNeeded();
-		$self->setupStage1D();
-	});
-	# creat the install-info file, in order to indicate a proper installation:
-	open(INFO, "> $installInfoFile")
-		or die _tr("unable to create info-file <%s> (%s)\n", $installInfoFile, $!);
-	print INFO "SLX_META_PACKAGER=$self->{distro}->{'meta-packager-type'}\n";
-	close(INFO);
+	callInSubprocess(
+		sub {
+			# another task that involves a chrooted environment:
+			$self->changePersonalityIfNeeded();
+			$self->setupStage1D();
+		}
+	);
+
+	# create the install-info file, in order to indicate a proper installation:
+	spitFile($installInfoFile,
+		"SLX_META_PACKAGER=$self->{distro}->{'meta-packager-type'}\n");
 	slxsystem("rm $baseSystemFile");
-		# no longer needed, we have a full system now
-	vlog(0, _tr("Vendor-OS '%s' installed succesfully.\n",
-				$self->{'vendor-os-name'}));
+
+	# no longer needed, we have a full system now
+	vlog(
+		0,
+		_tr(
+			"Vendor-OS '%s' installed succesfully.\n",
+			$self->{'vendor-os-name'}
+		)
+	);
 
 	$self->touchVendorOS();
 	$self->addInstalledVendorOSToConfigDB();
@@ -224,7 +268,7 @@ sub installVendorOS
 
 sub cloneVendorOS
 {
-	my $self = shift;
+	my $self   = shift;
 	my $source = shift;
 
 	if (substr($source, -1, 1) ne '/') {
@@ -241,9 +285,14 @@ sub cloneVendorOS
 		my $installInfoFile = "$self->{'vendor-os-path'}/.openslx-install-info";
 		if (-e $installInfoFile) {
 			# oops, given vendor-os has been installed, not cloned, we complain:
-			die _tr("The vendor-OS '%s' exists but it is no clone, refusing to clobber!\nPlease delete the folder manually, if that's really what you want...\n",
-					$self->{'vendor-os-path'});
-		} elsif (-e $cloneInfoFile) {
+			croak(
+				_tr(
+					"The vendor-OS '%s' exists but it is no clone, refusing to clobber!\nPlease delete the folder manually, if that's really what you want...\n",
+					$self->{'vendor-os-path'}
+				)
+			);
+		}
+		elsif (-e $cloneInfoFile) {
 			# check if last and current source match:
 			my $cloneInfo = slurpFile($cloneInfoFile);
 			if ($cloneInfo =~ m[^source\s*=\s*(.+?)\s*$]ims) {
@@ -252,14 +301,17 @@ sub cloneVendorOS
 			if ($source ne $lastCloneSource) {
 				# protect user from confusing sources (still allowed, though):
 				my $yes = _tr('yes');
-				my $no = _tr('no');
-				print _tr("Last time this vendor-OS was cloned, it has been cloned from '%s', now you specified a different source: '%s'\nWould you still like to proceed (%s/%s)? ",
-						$lastCloneSource, $source, $yes, $no);
+				my $no  = _tr('no');
+				print _tr(
+					"Last time this vendor-OS was cloned, it has been cloned from '%s', now you specified a different source: '%s'\nWould you still like to proceed (%s/%s)? ",
+					$lastCloneSource, $source, $yes, $no
+				);
 				my $answer = <STDIN>;
-				exit 5		unless $answer =~ m[^\s*$yes]i;
+				exit 5 unless $answer =~ m[^\s*$yes]i;
 			}
 			$isReClone = 1;
-		} else {
+		}
+		else {
 			# Neither the install-info nor the clone-info file exists. This
 			# probably means that the folder has been created by an older
 			# version of the tools. There's not much we can do, we simply
@@ -271,18 +323,25 @@ sub cloneVendorOS
 
 	$self->clone_fetchSource($source);
 	if ($source ne $lastCloneSource) {
-		open(CLONE_INFO, "> $cloneInfoFile")
-			or die _tr("unable to create clone-info file '%s', giving up! (%s)\n",
-					   $cloneInfoFile, $!);
-		print CLONE_INFO "source=$source";
-		close CLONE_INFO;
+		spitFile($cloneInfoFile, "source=$source\n");
 	}
 	if ($isReClone) {
-		vlog(0, _tr("Vendor-OS '%s' has been re-cloned succesfully.\n",
-					$self->{'vendor-os-name'}));
-	} else {
-		vlog(0, _tr("Vendor-OS '%s' has been cloned succesfully.\n",
-					$self->{'vendor-os-name'}));
+		vlog(
+			0,
+			_tr(
+				"Vendor-OS '%s' has been re-cloned succesfully.\n",
+				$self->{'vendor-os-name'}
+			)
+		);
+	}
+	else {
+		vlog(
+			0,
+			_tr(
+				"Vendor-OS '%s' has been cloned succesfully.\n",
+				$self->{'vendor-os-name'}
+			)
+		);
 	}
 
 	$self->touchVendorOS();
@@ -295,19 +354,23 @@ sub updateVendorOS
 
 	if (!-e $self->{'vendor-os-path'}) {
 		die _tr("can't update vendor-OS '%s', since it doesn't exist!\n",
-				$self->{'vendor-os-path'});
+			$self->{'vendor-os-path'});
 	}
 
 	$self->startLocalURLServersAsNeeded();
 
-	callInSubprocess( sub {
-		$self->changePersonalityIfNeeded();
-		$self->updateStage1D();
-	});
+	callInSubprocess(
+		sub {
+			$self->changePersonalityIfNeeded();
+			$self->updateStage1D();
+		}
+	);
 
 	$self->touchVendorOS();
-	vlog(0, _tr("Vendor-OS '%s' updated succesfully.\n",
-				$self->{'vendor-os-name'}));
+	vlog(
+		0,
+		_tr("Vendor-OS '%s' updated succesfully.\n", $self->{'vendor-os-name'})
+	);
 }
 
 sub startChrootedShellForVendorOS
@@ -315,32 +378,53 @@ sub startChrootedShellForVendorOS
 	my $self = shift;
 
 	if (!-e $self->{'vendor-os-path'}) {
-		die _tr("can't start chrooted shell for vendor-OS '%s', since it doesn't exist!\n",
-				$self->{'vendor-os-path'});
+		die _tr(
+			"can't start chrooted shell for vendor-OS '%s', since it doesn't exist!\n",
+			$self->{'vendor-os-path'}
+		);
 	}
 
 	$self->startLocalURLServersAsNeeded();
 
-	callInSubprocess( sub {
-		$self->changePersonalityIfNeeded();
-		$self->startChrootedShellInStage1D();
-	});
+	callInSubprocess(
+		sub {
+			$self->changePersonalityIfNeeded();
+			$self->startChrootedShellInStage1D();
+		}
+	);
 
 	$self->touchVendorOS();
-	vlog(0, _tr("Chrooted shell for vendor-OS '%s' has been closed.\n",
-				$self->{'vendor-os-name'}));
+	vlog(
+		0,
+		_tr(
+			"Chrooted shell for vendor-OS '%s' has been closed.\n",
+			$self->{'vendor-os-name'}
+		)
+	);
 }
 
 sub removeVendorOS
 {
 	my $self = shift;
 
-	vlog(0, _tr("removing vendor-OS folder '%s'...", $self->{'vendor-os-path'}));
+	vlog(
+		0,
+		_tr("removing vendor-OS folder '%s'...", $self->{'vendor-os-path'})
+	);
 	if (system("rm -r $self->{'vendor-os-path'}")) {
-		vlog(0, _tr("* unable to remove vendor-OS '%s'!", $self->{'vendor-os-path'}));
-	} else {
-		vlog(0, _tr("Vendor-OS '%s' removed succesfully.\n",
-					$self->{'vendor-os-name'}));
+		vlog(
+			0,
+			_tr("* unable to remove vendor-OS '%s'!", $self->{'vendor-os-path'})
+		);
+	}
+	else {
+		vlog(
+			0,
+			_tr(
+				"Vendor-OS '%s' removed succesfully.\n",
+				$self->{'vendor-os-name'}
+			)
+		);
 	}
 	$self->removeVendorOSFromConfigDB();
 }
@@ -350,37 +434,55 @@ sub addInstalledVendorOSToConfigDB
 	my $self = shift;
 
 	if (!-e $self->{'vendor-os-path'}) {
-		die _tr("can't import vendor-OS '%s', since it doesn't exist!\n",
-				$self->{'vendor-os-path'});
+		die _tr(
+			"can't import vendor-OS '%s', since it doesn't exist!\n",
+			$self->{'vendor-os-path'}
+		);
 	}
 	my $openslxDB = instantiateClass("OpenSLX::ConfigDB");
 	$openslxDB->connect();
+
 	# insert new vendor-os if it doesn't already exist in DB:
 	my $vendorOSName = $self->{'vendor-os-name'};
-	my $vendorOS
-		= $openslxDB->fetchVendorOSByFilter({ 'name' => $vendorOSName });
+	my $vendorOS = $openslxDB->fetchVendorOSByFilter({'name' => $vendorOSName});
 	if (defined $vendorOS) {
 		if ($self->{'clone-source'} ne $vendorOS->{'clone_source'}) {
-			$openslxDB->changeVendorOS($vendorOS->{id}, {
-				'clone_source' => $self->{'clone-source'},
-			});
-			vlog(0, _tr("Vendor-OS '%s' has been updated in OpenSLX-database.\n",
-						$vendorOSName));
-		} else {
-			vlog(0, _tr("No need to change vendor-OS '%s' in OpenSLX-database.\n",
-						$vendorOSName));
+			$openslxDB->changeVendorOS(
+				$vendorOS->{id},
+				{ 'clone_source' => $self->{'clone-source'} }
+			);
+			vlog(
+				0,
+				_tr(
+					"Vendor-OS '%s' has been updated in OpenSLX-database.\n",
+					$vendorOSName
+				)
+			);
 		}
-	} else {
-		my $data = {
-			'name' => $vendorOSName,
-		};
+		else {
+			vlog(
+				0,
+				_tr(
+					"No need to change vendor-OS '%s' in OpenSLX-database.\n",
+					$vendorOSName
+				)
+			);
+		}
+	}
+	else {
+		my $data = {'name' => $vendorOSName,};
 		if (length($self->{'clone-source'})) {
 			$data->{'clone_source'} = $self->{'clone-source'};
 		}
 		my $id = $openslxDB->addVendorOS($data);
 
-		vlog(0, _tr("Vendor-OS '%s' has been added to DB (ID=%s).\n",
-					$vendorOSName, $id));
+		vlog(
+			0,
+			_tr(
+				"Vendor-OS '%s' has been added to DB (ID=%s).\n",
+				$vendorOSName, $id
+			)
+		);
 	}
 
 	$openslxDB->disconnect();
@@ -394,28 +496,39 @@ sub removeVendorOSFromConfigDB
 	$openslxDB->connect();
 
 	my $vendorOSName = $self->{'vendor-os-name'};
-	my $vendorOS
-		= $openslxDB->fetchVendorOSByFilter({ 'name' => $vendorOSName });
+	my $vendorOS = $openslxDB->fetchVendorOSByFilter({'name' => $vendorOSName});
 	if (!defined $vendorOS) {
-		vlog(0, _tr("Vendor-OS '%s' didn't exist in OpenSLX-database.\n",
-					$vendorOSName));
-	} else {
+		vlog(
+			0,
+			_tr(
+				"Vendor-OS '%s' didn't exist in OpenSLX-database.\n",
+				$vendorOSName
+			)
+		);
+	}
+	else {
 		# remove all exports (and systems) using this vendor-OS and then
 		# remove the vendor-OS itself:
-		my @exports	= $openslxDB->fetchExportByFilter(
-			{ 'vendor_os_id' => $vendorOS->{id} }
-		);
+		my @exports = $openslxDB->fetchExportByFilter(
+			{'vendor_os_id' => $vendorOS->{id}});
 		foreach my $export (@exports) {
 			my $osExportEngine = instantiateClass("OpenSLX::OSExport::Engine");
 			$osExportEngine->initializeFromExisting($export->{name});
-			vlog(0, _tr("purging export '%s', since it belongs to the vendor-OS being deleted...",
-						$export->{name}));
+			vlog(
+				0,
+				_tr(
+					"purging export '%s', since it belongs to the vendor-OS being deleted...",
+					$export->{name}
+				)
+			);
 			$osExportEngine->purgeExport();
 		}
 
 		$openslxDB->removeVendorOS($vendorOS->{id});
-		vlog(0, _tr("Vendor-OS '%s' has been removed from DB!\n",
-					$vendorOSName));
+		vlog(
+			0,
+			_tr("Vendor-OS '%s' has been removed from DB!\n", $vendorOSName)
+		);
 	}
 
 	$openslxDB->disconnect();
@@ -429,46 +542,51 @@ sub readDistroInfo
 	my $self = shift;
 
 	vlog(1, "reading configuration info for $self->{'vendor-os-name'}...");
+
 	# merge user-provided configuration distro defaults...
 	my %repository = %{$self->{distro}->{config}->{repository}};
-	my %selection = %{$self->{distro}->{config}->{selection}};
-	my %excludes =
-		defined $self->{distro}->{config}->{excludes}
+	my %selection  = %{$self->{distro}->{config}->{selection}};
+	my %excludes 
+		= defined $self->{distro}->{config}->{excludes}
 			? %{$self->{distro}->{config}->{excludes}}
 			: ();
-	my $package_subdir = $self->{distro}->{config}->{'package-subdir'};
+	my $package_subdir  = $self->{distro}->{config}->{'package-subdir'};
 	my $prereq_packages = $self->{distro}->{config}->{'prereq-packages'};
-	my $bootstrap_prereq_packages
-		= $self->{distro}->{config}->{'bootstrap-prereq-packages'};
+	my $bootstrap_prereq_packages =
+		$self->{distro}->{config}->{'bootstrap-prereq-packages'};
 	my $bootstrap_packages = $self->{distro}->{config}->{'bootstrap-packages'};
-	my $metapackager_packages 
-		= $self->{distro}->{config}->{'metapackager-packages'};
+	my $metapackager_packages =
+		$self->{distro}->{config}->{'metapackager-packages'};
 	my $file = "$self->{'config-distro-info-dir'}/settings";
+
 	if (-e $file) {
 		vlog(2, "reading configuration file $file...");
 		my $config = slurpFile($file);
-		if (!eval $config && length($@)) {
-			die _tr("error in config-file '%s' (%s)", $file, $@)."\n";
+		if (!eval { $config } && length($@)) {
+			die _tr("error in config-file '%s' (%s)", $file, $@) . "\n";
 		}
 	}
+
 	# ...expand selection definitions...
 	foreach my $selKey (keys %selection) {
 		$selection{$selKey} =~ s[<<<([^>]+)>>>][$selection{$1}]eg;
 	}
+
 	# ...expand selection definitions...
 	foreach my $exclKey (keys %excludes) {
 		$excludes{$exclKey} =~ s[<<<([^>]+)>>>][$excludes{$1}]eg;
 	}
+
 	# ...and store merged config:
 	$self->{'distro-info'} = {
-		'package-subdir' => $package_subdir,
-		'prereq-packages' => $prereq_packages,
+		'package-subdir'            => $package_subdir,
+		'prereq-packages'           => $prereq_packages,
 		'bootstrap-prereq-packages' => $bootstrap_prereq_packages,
-		'bootstrap-packages' => $bootstrap_packages,
-		'metapackager-packages' => $metapackager_packages,
-		'repository' => \%repository,
-		'selection' => \%selection,
-		'excludes' => \%excludes,
+		'bootstrap-packages'        => $bootstrap_packages,
+		'metapackager-packages'     => $metapackager_packages,
+		'repository'                => \%repository,
+		'selection'                 => \%selection,
+		'excludes'                  => \%excludes,
 	};
 
 	if ($openslxConfig{'verbose-level'} >= 2) {
@@ -502,7 +620,7 @@ sub createVendorOSPath
 
 	if (slxsystem("mkdir -p $self->{'vendor-os-path'}")) {
 		die _tr("unable to create directory '%s', giving up! (%s)\n",
-				$self->{'vendor-os-path'}, $!);
+			$self->{'vendor-os-path'}, $!);
 	}
 }
 
@@ -520,7 +638,7 @@ sub createPackager
 {
 	my $self = shift;
 
-	my $packagerClass
+	my $packagerClass 
 		= "OpenSLX::OSSetup::Packager::$self->{distro}->{'packager-type'}";
 	my $packager = instantiateClass($packagerClass);
 	$packager->initialize($self);
@@ -542,29 +660,30 @@ sub createMetaPackager
 		}
 	}
 
-	my $metaPackagerClass
-		= "OpenSLX::OSSetup::MetaPackager::$metaPackagerType";
-	my $metaPackager =instantiateClass($metaPackagerClass);
+	my $metaPackagerClass = "OpenSLX::OSSetup::MetaPackager::$metaPackagerType";
+	my $metaPackager      = instantiateClass($metaPackagerClass);
 	$metaPackager->initialize($self);
 	$self->{'meta-packager'} = $metaPackager;
 }
 
 sub sortRepositoryURLs
 {
-	my $self = shift;
+	my $self     = shift;
 	my $repoInfo = shift;
 
-	if ($repoInfo->{'url'} =~ m[^local:]) {
+	if (defined $repoInfo->{'url'} && $repoInfo->{'url'} =~ m[^local:]) {
 		# a local URL blocks all the others, in order to avoid causing
 		# (external) network traffic:
-		my $localURL = $repoInfo->{'url'};
+		my $localURL = $repoInfo->{'url'} || '';
 		$localURL =~ s[^local:][http:];
-		return [ $localURL ];
+		return [$localURL];
 	}
 
 	my %urlInfo;
+
 	# specified URL always has highest precedence:
-	$urlInfo{$repoInfo->{url}} = 0		if defined $repoInfo->{url};
+	$urlInfo{$repoInfo->{url}} = 0 if defined $repoInfo->{url};
+
 	# now add all others sorted by "closeness":
 	my $index = 1;
 	foreach my $url (string2Array($repoInfo->{urls})) {
@@ -577,11 +696,11 @@ sub sortRepositoryURLs
 
 sub downloadBaseFiles
 {
-	my $self = shift;
+	my $self  = shift;
 	my $files = shift;
 
-	my $pkgSubdir = $self->{'distro-info'}->{'package-subdir'};
-	my @URLs = @{$self->{'baseURLs'}};
+	my $pkgSubdir   = $self->{'distro-info'}->{'package-subdir'};
+	my @URLs        = @{$self->{'baseURLs'}};
 	my $maxTryCount = $openslxConfig{'ossetup-max-try-count'};
 
 	my @foundFiles;
@@ -589,18 +708,20 @@ sub downloadBaseFiles
 		my $tryCount = 0;
 		next unless $fileVariantStr =~ m[\S];
 		my $foundFile;
-try_next_url:
+	  try_next_url:
 		my $url = $URLs[$self->{'baseURL-index'}];
-		$url .= "/$pkgSubdir"	if length($pkgSubdir);
+		$url .= "/$pkgSubdir" if length($pkgSubdir);
 		my @contFlags = ();
-		push @contFlags, '-c'	if ($url =~ m[^ftp]);
-			# continuing is only supported with FTP, but not with HTTP
+		push @contFlags, '-c' if ($url =~ m[^ftp]);
+
+		# continuing is only supported with FTP, but not with HTTP
 		foreach my $file (split '\s+', $fileVariantStr) {
 			vlog(2, "fetching <$file>...");
 			if (slxsystem("wget", @contFlags, "$url/$file") == 0) {
 				$foundFile = basename($file);
 				last;
-			} elsif ($! == 17) {
+			}
+			elsif ($! == 17) {
 				my $basefile = basename($file);
 				vlog(2, "removing left-over '$basefile' and trying again...");
 				unlink $basefile;
@@ -609,14 +730,18 @@ try_next_url:
 		if (!defined $foundFile) {
 			if (!$ENV{SLX_NO_MIRRORS} && $tryCount < $maxTryCount) {
 				$tryCount++;
-				$self->{'baseURL-index'}
-					= ($self->{'baseURL-index'}+1) % scalar(@URLs);
-				vlog(0, _tr("switching to mirror '%s'.",
-							$URLs[$self->{'baseURL-index'}]));
+				$self->{'baseURL-index'} 
+					= ($self->{'baseURL-index'} + 1) % scalar(@URLs);
+				vlog(
+					0,
+					_tr(
+						"switching to mirror '%s'.",
+						$URLs[$self->{'baseURL-index'}]
+					)
+				);
 				goto try_next_url;
 			}
-			die _tr("unable to fetch '%s' from any source!\n",
-					$fileVariantStr);
+			die _tr("unable to fetch '%s' from any source!\n", $fileVariantStr);
 		}
 		push @foundFiles, $foundFile;
 	}
@@ -630,25 +755,23 @@ sub startLocalURLServersAsNeeded
 	$self->{'local-http-server-master-pid'} = $$;
 
 	foreach my $repoInfo (values %{$self->{'distro-info'}->{repository}}) {
-		
-		next unless $repoInfo->{'url'} =~ m[^local:];
-		my $localURL = $repoInfo->{url};
+		my $localURL = $repoInfo->{url} || '';
+		next unless $localURL =~ m[^local:];
 		if (!exists $self->{'local-http-servers'}->{$localURL}) {
-			my $busyboxName
-				= $self->hostIs64Bit()
-					? 'busybox.x86_64'
-					: 'busybox.i586';
-			my $busybox = "$openslxConfig{'base-path'}/share/busybox/$busyboxName";
+			my $busyboxName =
+				$self->hostIs64Bit()
+				? 'busybox.x86_64'
+				: 'busybox.i586';
+			my $busybox =
+				"$openslxConfig{'base-path'}/share/busybox/$busyboxName";
 			my $port = 5080;
 			if ($localURL =~ m[:(\d+)/]) {
 				$port = $1;
 			}
-			my $pid = executeInSubprocess(
-				$busybox, "httpd",
-				'-p', $port, 
-				'-h', '/',
-				'-f'
-			);
+			my $pid 
+				= executeInSubprocess(
+					$busybox, "httpd", '-p', $port, '-h', '/', '-f'
+				);
 			vlog(1, _tr("started local HTTP-server for URL '%s'.", $localURL));
 			$self->{'local-http-servers'}->{$localURL} = $pid;
 		}
@@ -662,16 +785,16 @@ sub setupStage1A
 	vlog(1, "setting up stage1a for $self->{'vendor-os-name'}...");
 
 	# specify individual paths for the respective substages:
-	$self->{stage1aDir} = "$self->{'vendor-os-path'}/stage1a";
+	$self->{stage1aDir}    = "$self->{'vendor-os-path'}/stage1a";
 	$self->{stage1bSubdir} = 'slxbootstrap';
 	$self->{stage1cSubdir} = 'slxfinal';
 
 	# we create *all* of the above folders by creating stage1cDir:
-	my $stage1cDir
+	my $stage1cDir 
 		= "$self->{'stage1aDir'}/$self->{'stage1bSubdir'}/$self->{'stage1cSubdir'}";
 	if (slxsystem("mkdir -p $stage1cDir")) {
 		die _tr("unable to create directory '%s', giving up! (%s)\n",
-				$stage1cDir, $!);
+			$stage1cDir, $!);
 	}
 
 	$self->stage1A_createBusyboxEnvironment();
@@ -686,22 +809,22 @@ sub stage1A_createBusyboxEnvironment
 
 	# copy busybox and all required binaries into stage1a-dir:
 	vlog(1, "creating busybox-environment...");
-	my $busyboxName
-		= $self->hostIs64Bit()
-			? 'busybox.x86_64'
-			: 'busybox.i586';
-	copyFile("$openslxConfig{'base-path'}/share/busybox/$busyboxName",
-			 "$self->{stage1aDir}/bin", 'busybox');
+	my $busyboxName = $self->hostIs64Bit() ? 'busybox.x86_64' : 'busybox.i586';
+	copyFile(
+		"$openslxConfig{'base-path'}/share/busybox/$busyboxName",
+		"$self->{stage1aDir}/bin", 'busybox'
+	);
 
 	# determine all required libraries and copy those, too:
 	vlog(1, _tr("calling slxldd for $busyboxName"));
-	my $slxlddCmd
+	my $slxlddCmd 
 		= "slxldd $openslxConfig{'base-path'}/share/busybox/$busyboxName";
 	vlog(2, "executing: $slxlddCmd");
 	my $requiredLibsStr = `$slxlddCmd`;
 	if ($?) {
-		die _tr("slxldd couldn't determine the libs required by busybox! (%s)",
-				$?);
+		die _tr(
+			"slxldd couldn't determine the libs required by busybox! (%s)", $?
+		);
 	}
 	chomp $requiredLibsStr;
 	vlog(2, "slxldd results:\n$requiredLibsStr");
@@ -718,16 +841,18 @@ sub stage1A_createBusyboxEnvironment
 	}
 
 	# create all needed links to busybox:
-	my $links
+	my $links 
 		= slurpFile("$openslxConfig{'base-path'}/share/busybox/busybox.links");
 	foreach my $linkTarget (split "\n", $links) {
 		linkFile('/bin/busybox', "$self->{stage1aDir}/$linkTarget");
 	}
-	if ($self->hostIs64Bit() && !-e "$self->{stage1aDir}/lib64") {
-		linkFile('/lib', "$self->{stage1aDir}/lib64");
-	}
-	if ($self->hostIs64Bit() && !-e "$self->{stage1aDir}/usr/lib64") {
-		linkFile('/usr/lib', "$self->{stage1aDir}/usr/lib64");
+	if ($self->hostIs64Bit()) { 
+		if (!-e "$self->{stage1aDir}/lib64") {
+			linkFile('/lib', "$self->{stage1aDir}/lib64");
+		}
+		if (!-e "$self->{stage1aDir}/usr/lib64") {
+			linkFile('/usr/lib', "$self->{stage1aDir}/usr/lib64");
+		}
 	}
 
 	$self->stage1A_setupResolver($libcFolder);
@@ -735,7 +860,7 @@ sub stage1A_createBusyboxEnvironment
 
 sub stage1A_setupResolver
 {
-	my $self = shift;
+	my $self       = shift;
 	my $libcFolder = shift;
 
 	if (!defined $libcFolder) {
@@ -743,11 +868,11 @@ sub stage1A_setupResolver
 		$libcFolder = '/lib';
 	}
 
-	copyFile('/etc/resolv.conf', "$self->{stage1aDir}/etc");
-	copyFile("$libcFolder/libresolv*", "$self->{stage1aDir}$libcFolder");
+	copyFile('/etc/resolv.conf',        "$self->{stage1aDir}/etc");
+	copyFile("$libcFolder/libresolv*",  "$self->{stage1aDir}$libcFolder");
 	copyFile("$libcFolder/libnss_dns*", "$self->{stage1aDir}$libcFolder");
 
-	my $stage1cDir
+	my $stage1cDir 
 		= "$self->{'stage1aDir'}/$self->{'stage1bSubdir'}/$self->{'stage1cSubdir'}";
 	copyFile('/etc/resolv.conf', "$stage1cDir/etc");
 }
@@ -759,15 +884,17 @@ sub stage1A_copyPrerequiredFiles
 	return unless -d "$self->{'shared-distro-info-dir'}/prereqfiles";
 
 	vlog(2, "copying folder with pre-required files...");
-	my $stage1cDir
+	my $stage1cDir 
 		= "$self->{'stage1aDir'}/$self->{'stage1bSubdir'}/$self->{'stage1cSubdir'}";
 	my $cmd = qq[
 		tar -cp -C $self->{'shared-distro-info-dir'}/prereqfiles . \\
 		| tar -xp -C $stage1cDir
 	];
 	if (slxsystem($cmd)) {
-		die _tr("unable to copy folder with pre-required files to folder '%s' (%s)\n",
-				$stage1cDir, $!);
+		die _tr(
+			"unable to copy folder with pre-required files to folder '%s' (%s)\n",
+			$stage1cDir, $!
+		);
 	}
 	$self->{distro}->fixPrerequiredFiles($stage1cDir);
 }
@@ -777,10 +904,9 @@ sub stage1A_copyTrustedPackageKeys
 	my $self = shift;
 
 	vlog(2, "copying folder with trusted package keys...");
-	my $stage1bDir
-		= "$self->{'stage1aDir'}/$self->{'stage1bSubdir'}";
+	my $stage1bDir = "$self->{'stage1aDir'}/$self->{'stage1bSubdir'}";
 	foreach my $folder (
-		$self->{'shared-distro-info-dir'}, $self->{'config-distro-info-dir'},
+		$self->{'shared-distro-info-dir'}, $self->{'config-distro-info-dir'}
 	) {
 		next unless -d "$folder/trusted-package-keys";
 		my $cmd = qq[
@@ -788,14 +914,15 @@ sub stage1A_copyTrustedPackageKeys
 		| tar -xp -C $stage1bDir
 		];
 		if (slxsystem($cmd)) {
-			die _tr("unable to copy folder with trusted package keys to folder '%s' (%s)\n",
-					"$stage1bDir/trusted-package-keys", $!);
+			die _tr(
+				"unable to copy folder with trusted package keys to folder '%s' (%s)\n",
+				"$stage1bDir/trusted-package-keys", $!
+			);
 		}
 		slxsystem("chmod 444 $stage1bDir/trusted-package-keys/*");
 
 		# install ultimately trusted keys (from distributor):
-		my $stage1cDir
-			= "$stage1bDir/$self->{'stage1cSubdir'}";
+		my $stage1cDir = "$stage1bDir/$self->{'stage1cSubdir'}";
 		my $keyDir = "$self->{'shared-distro-info-dir'}/trusted-package-keys";
 		if (-e "$keyDir/pubring.gpg") {
 			copyFile("$keyDir/pubring.gpg", "$stage1cDir/usr/lib/rpm/gnupg");
@@ -808,23 +935,26 @@ sub stage1A_createRequiredFiles
 	my $self = shift;
 
 	vlog(2, "creating required files...");
+
 	# fake all files required by stage1b (by creating them empty):
-	my $stage1bDir
-		= "$self->{'stage1aDir'}/$self->{'stage1bSubdir'}";
+	my $stage1bDir = "$self->{'stage1aDir'}/$self->{'stage1bSubdir'}";
 	foreach my $fake (@{$self->{distro}->{'stage1b-faked-files'}}) {
 		fakeFile("$stage1bDir/$fake");
 	}
 
 	# fake all files required by stage1c (by creating them empty):
-	my $stage1cDir
-		= "$stage1bDir/$self->{'stage1cSubdir'}";
+	my $stage1cDir = "$stage1bDir/$self->{'stage1cSubdir'}";
 	foreach my $fake (@{$self->{distro}->{'stage1c-faked-files'}}) {
 		fakeFile("$stage1cDir/$fake");
 	}
 
 	mkdir "$stage1cDir/dev";
-	if (!-e "$stage1cDir/dev/null" && slxsystem("mknod $stage1cDir/dev/null c 1 3")) {
-		die _tr("unable to create node '%s' (%s)\n", "$stage1cDir/dev/null", $!);
+	if (!-e "$stage1cDir/dev/null"
+		&& slxsystem("mknod $stage1cDir/dev/null c 1 3"))
+	{
+		die _tr(
+			"unable to create node '%s' (%s)\n", "$stage1cDir/dev/null", $!
+		);
 	}
 }
 
@@ -844,11 +974,15 @@ sub stage1B_chrootAndBootstrap
 
 	# chdir into slxbootstrap, as we want to drop packages into there:
 	chdir "/$self->{stage1bSubdir}"
-		or die _tr("unable to chdir into '%s' (%s)\n", "/$self->{stage1bSubdir}", $!);
+		or die _tr(
+			"unable to chdir into '%s' (%s)\n", "/$self->{stage1bSubdir}", $!
+		);
 
 	# fetch prerequired packages:
-	$self->{'baseURLs'}
-		= $self->sortRepositoryURLs($self->{'distro-info'}->{repository}->{base});
+	$self->{'baseURLs'} 
+		= $self->sortRepositoryURLs(
+			$self->{'distro-info'}->{repository}->{base}
+		  );
 	$self->{'baseURL-index'} = 0;
 	my @pkgs = string2Array($self->{'distro-info'}->{'prereq-packages'});
 	my @prereqPkgs = $self->downloadBaseFiles(\@pkgs);
@@ -859,14 +993,16 @@ sub stage1B_chrootAndBootstrap
 	$self->{'bootstrap-prereq-packages'} = \@bootstrapPrereqPkgs;
 
 	@pkgs = string2Array($self->{'distro-info'}->{'bootstrap-packages'});
-	push @pkgs, string2Array(
-		$self->{'distro-info'}->{'metapackager-packages'}->{
-			$self->{distro}->{'meta-packager-type'}
-		}
+	push(
+		@pkgs, 
+		string2Array(
+			$self->{'distro-info'}->{'metapackager-packages'}
+				->{$self->{distro}->{'meta-packager-type'}}
+		)
 	);
 	my @bootstrapPkgs = $self->downloadBaseFiles(\@pkgs);
 	my @allPkgs = (@prereqPkgs, @bootstrapPrereqPkgs, @bootstrapPkgs);
-	$self->{'bootstrap-packages'}	= \@allPkgs;
+	$self->{'bootstrap-packages'} = \@allPkgs;
 }
 
 sub setupStage1C
@@ -885,20 +1021,23 @@ sub stage1C_chrootAndInstallBasicVendorOS
 	chrootInto($stage1bDir);
 
 	my $stage1cDir = "/$self->{stage1cSubdir}";
+
 	# install all prerequired bootstrap packages
 	$self->{packager}->installPrerequiredPackages(
-		$self->{'bootstrap-prereq-packages'}, $stage1cDir
+		$self->{'bootstrap-prereq-packages'},
+		$stage1cDir
 	);
 
 	# import any additional trusted package keys to rpm-DB:
 	my $keyDir = "/trusted-package-keys";
-	opendir(KEYDIR, $keyDir)
+	my $keyDirDH;
+	opendir($keyDirDH, $keyDir)
 		or die _tr("unable to opendir '%s' (%s)\n", $keyDir, $!);
-	my @keyFiles
+	my @keyFiles 
 		= map { "$keyDir/$_" }
-		  grep { $_ !~ m[^(\.\.?|pubring.gpg)$] }
-		  readdir(KEYDIR);
-	closedir(KEYDIR);
+		  grep { $_ !~ m[^(\.\.?|pubring.gpg)$] } 
+		  readdir($keyDirDH);
+	closedir($keyDirDH);
 	$self->{packager}->importTrustedPackageKeys(\@keyFiles, $stage1cDir);
 
 	# install all other bootstrap packages
@@ -911,15 +1050,19 @@ sub stage1C_cleanupBasicVendorOS
 {
 	my $self = shift;
 
-	my $stage1cDir
+	my $stage1cDir 
 		= "$self->{'stage1aDir'}/$self->{'stage1bSubdir'}/$self->{'stage1cSubdir'}";
 	if (slxsystem("mv $stage1cDir/* $self->{'vendor-os-path'}/")) {
-		die _tr("unable to move final setup to '%s' (%s)\n",
-				$self->{'vendor-os-path'}, $!);
+		die _tr(
+			"unable to move final setup to '%s' (%s)\n",
+			$self->{'vendor-os-path'}, $!
+		);
 	}
 	if (slxsystem("rm -rf $self->{stage1aDir}")) {
-		die _tr("unable to remove temporary folder '%s' (%s)\n",
-				$self->{stage1aDir}, $!);
+		die _tr(
+			"unable to remove temporary folder '%s' (%s)\n",
+			$self->{stage1aDir}, $!
+		);
 	}
 }
 
@@ -960,28 +1103,29 @@ sub startChrootedShellInStage1D
 
 	$self->{'meta-packager'}->startSession();
 	slxsystem('sh');
-		# hangs until user exits manually
+
+	# hangs until user exits manually
 	$self->{'distro'}->updateDistroConfig();
 	$self->{'meta-packager'}->finishSession();
 }
 
-sub stage1D_setupPackageSources()
+sub stage1D_setupPackageSources
 {
 	my $self = shift;
 
 	vlog(1, "setting up package sources for meta packager...");
 	my $selectionName = $self->{'selection-name'};
-	my $pkgExcludes = $self->{'distro-info'}->{excludes}->{$selectionName};
-	my $excludeList = join ' ', string2Array($pkgExcludes);
+	my $pkgExcludes   = $self->{'distro-info'}->{excludes}->{$selectionName};
+	my $excludeList   = join ' ', string2Array($pkgExcludes);
 	$self->{'meta-packager'}->initPackageSources();
 	my ($rk, $repo);
-	while(($rk, $repo) = each %{$self->{'distro-info'}->{repository}}) {
+	while (($rk, $repo) = each %{$self->{'distro-info'}->{repository}}) {
 		vlog(2, "setting up package source $rk...");
 		$self->{'meta-packager'}->setupPackageSource($rk, $repo, $excludeList);
 	}
 }
 
-sub stage1D_updateBasicVendorOS()
+sub stage1D_updateBasicVendorOS
 {
 	my $self = shift;
 
@@ -999,22 +1143,27 @@ sub stage1D_installPackageSelection
 	my $selectionName = $self->{'selection-name'};
 
 	vlog(1, "installing package selection <$selectionName>...");
-	my $pkgSelection = $self->{'distro-info'}->{selection}->{$selectionName};
-	my @pkgs = string2Array($pkgSelection);
+	my $pkgSelection  = $self->{'distro-info'}->{selection}->{$selectionName};
+	my @pkgs          = string2Array($pkgSelection);
 	my @installedPkgs = $self->{'packager'}->getInstalledPackages();
-	@pkgs 
-		= 	grep {
-				my $pkg = $_;
-				if (grep { $_ eq $pkg; } @installedPkgs) {
-					vlog(1, "package '$pkg' filtered, it is already installed.");
-					0;
-				} else {
-					1;
-				}
-			} @pkgs;
-		vlog(0, _tr("No packages listed for selection '%s', nothing to do.",
-					$selectionName));
-   	vlog(1, "installing these packages:\n".join("\n\t", @pkgs));
+	@pkgs = grep {
+		my $pkg = $_;
+		if (grep { $_ eq $pkg; } @installedPkgs) {
+			vlog(1, "package '$pkg' filtered, it is already installed.");
+			0;
+		}
+		else {
+			1;
+		}
+	} @pkgs;
+	vlog(
+		0,
+		_tr(
+			"No packages listed for selection '%s', nothing to do.",
+			$selectionName
+		)
+	);
+	vlog(1, "installing these packages:\n" . join("\n\t", @pkgs));
 	$self->{'meta-packager'}->startSession();
 	if (scalar(@pkgs) > 0) {
 		$self->{'meta-packager'}->installSelection(join " ", @pkgs);
@@ -1025,54 +1174,69 @@ sub stage1D_installPackageSelection
 
 sub clone_fetchSource
 {
-	my $self = shift;
+	my $self   = shift;
 	my $source = shift;
 
-	vlog(0, _tr("Cloning vendor-OS from '%s' to '%s'...\n", $source,
-				$self->{'vendor-os-path'}));
+	vlog(
+		0,
+		_tr(
+			"Cloning vendor-OS from '%s' to '%s'...\n", $source,
+			$self->{'vendor-os-path'}
+		)
+	);
 	my $excludeIncludeList = $self->clone_determineIncludeExcludeList();
 	vlog(1, "using exclude-include-filter:\n$excludeIncludeList\n");
-	my $rsyncCmd
+	my $rsyncCmd 
 		= "rsync -av --delete --exclude-from=- $source $self->{'vendor-os-path'}";
 	vlog(2, "executing: $rsyncCmd\n");
-	open(RSYNC, "| $rsyncCmd")
-		or die _tr("unable to start rsync for source '%s', giving up! (%s)\n",
-				   $source, $!);
-	print RSYNC $excludeIncludeList;
-	if (!close(RSYNC)) {
-		die _tr("unable to clone from source '%s', giving up! (%s)\n",
-				$source, $!);
-	}
+	my $rsyncFH;
+	open($rsyncFH, '|-', $rsyncCmd)
+		or croak(
+			_tr(
+				"unable to start rsync for source '%s', giving up! (%s)\n",
+				$source, $!
+			)
+		);
+	print $rsyncFH $excludeIncludeList;
+	close($rsyncFH)
+		or croak _tr(
+			"unable to clone from source '%s', giving up! (%s)\n", $source, $!
+		);
 }
 
 sub clone_determineIncludeExcludeList
 {
 	my $self = shift;
 
-	my $localFilterFile
+	my $localFilterFile 
 		= "$openslxConfig{'config-path'}/distro-info/clone-filter";
-	my $includeExcludeList = slurpFile($localFilterFile, 1);
+	my $includeExcludeList 
+		= slurpFile($localFilterFile, { failIfMissing => 0 });
 	$includeExcludeList .= $self->{distro}->{'clone-filter'};
 	$includeExcludeList =~ s[^\s+][]igms;
-		# remove any leading whitespace, as rsync doesn't like it
+
+	# remove any leading whitespace, as rsync doesn't like it
 	return $includeExcludeList;
 }
 
 ################################################################################
 ### utility methods
 ################################################################################
-sub changePersonalityIfNeeded {
+sub changePersonalityIfNeeded
+{
 	my $self = shift;
 
 	my $distroName = $self->{distro}->{'base-name'};
 	if ($self->hostIs64Bit() && $distroName !~ m[_64]) {
 		# trying to handle a 32-bit vendor-OS on a 64-bit machine, so we change
 		# the personality accordingly (from 64-bit to 32-bit):
-		require 'syscall.ph'
-			or die _tr("unable to load '%s'\n", 'syscall.ph');
-		require 'linux/personality.ph'
-			or die _tr("unable to load '%s'\n", 'linux/personality.ph');
-		no strict;
+		my $syscallPH = 'syscall.ph';
+		eval { require $syscallPH }
+			or die _tr("unable to load '%s'\n", $syscallPH);
+		my $personalityPH = 'linux/personality.ph';
+		eval { require $personalityPH }
+			or die _tr("unable to load '%s'\n", $personalityPH);
+
 		syscall &SYS_personality, PER_LINUX32();
 	}
 }
@@ -1081,7 +1245,7 @@ sub hostIs64Bit
 {
 	my $self = shift;
 
-	$self->{arch} = `uname -m`		unless defined $self->{arch};
+	$self->{arch} = `uname -m` unless defined $self->{arch};
 	return ($self->{arch} =~ m[64]);
 }
 
@@ -1090,13 +1254,16 @@ sub hostIs64Bit
 ################################################################################
 sub string2Array
 {
-	my $str = shift;
+	my $string = shift || '';
+
+	my @lines = split m[\n], $string;
+	for my $line (@lines) {
+		# remove leading and trailing whitespace:
+		$line =~ s{^\s*(.*?)\s*$}{$1};
+	}
 
-	return
-		grep { length($_) > 0 && $_ !~ m[^\s*#]; }
-            # drop empty lines and comments
-		map { $_ =~ s[^\s*(.*?)\s*$][$1]; $_ }
-		split "\n", $str;
+	# drop empty lines and comments:
+	return grep { length($_) > 0 && $_ !~ m[^\s*#]; } @lines;
 }
 
 sub chrootInto
@@ -1106,6 +1273,7 @@ sub chrootInto
 	vlog(2, "chrooting into $osDir...");
 	chdir $osDir
 		or die _tr("unable to chdir into '%s' (%s)\n", $osDir, $!);
+
 	# ...do chroot
 	chroot "."
 		or die _tr("unable to chroot into '%s' (%s)\n", $osDir, $!);
@@ -1127,3 +1295,4 @@ OpenSLX::OSSetup::Engine - driver engine for OSSetup API
 ...
 
 =cut
+