add --logfile option

coverage.sh

@@ -672,6 +672,28 @@ else
 	./run_null.sh SUDO
 fi
 
+print_header "mode=root,variant=apt: --logfile"
+cat << END > shared/test.sh
+#!/bin/sh
+set -eu
+export LC_ALL=C.UTF-8
+$CMD --mode=root --variant=apt --logfile=log unstable /tmp/debian-unstable $mirror
+tar -C /tmp/debian-unstable --one-file-system -c . | tar -t | sort > tar2.txt
+grep --quiet "I: running apt-get update..." log
+grep --quiet "I: downloading packages with apt..." log
+grep --quiet "I: extracting archives..." log
+grep --quiet "I: installing packages..." log
+grep --quiet "I: cleaning package lists and apt cache..." log
+diff -u tar1.txt tar2.txt
+rm -r /tmp/debian-unstable
+rm log
+END
+if [ "$HAVE_QEMU" = "yes" ]; then
+	./run_qemu.sh
+else
+	./run_null.sh SUDO
+fi
+
 # test all variants
 
 for variant in essential apt required minbase buildd important debootstrap - standard; do

mmdebstrap

@@ -1695,6 +1695,7 @@ sub main() {
 	customize_hook => [],
     };
     chomp ($options->{architectures} = `dpkg --print-architecture`);
+    my $logfile = undef;
     Getopt::Long::Configure ('default', 'bundling', 'auto_abbrev', 'ignore_case_always');
     GetOptions(
 	'h|help'   => sub { pod2usage(-exitval => 0, -verbose => 2) },
@@ -1709,6 +1710,7 @@ sub main() {
 	'q|quiet' => sub { $verbosity_level = 0; },
 	'v|verbose' => sub { $verbosity_level = 2; },
 	'd|debug' => sub { $verbosity_level = 3; },
+	'logfile=s' => \$logfile,
 	# no-op options so that mmdebstrap can be used with
 	# sbuild-createchroot --debootstrap=mmdebstrap
 	'resolve-deps' => sub { push @{$options->{noop}}, 'resolve-deps'; },
@@ -1720,6 +1722,10 @@ sub main() {
 	'customize-hook=s@' => \$options->{customize_hook},
     ) or pod2usage(-exitval => 2, -verbose => 1);
 
+    if (defined($logfile)) {
+	open(STDERR, '>', $logfile) or error "cannot open $logfile: $!";
+    }
+
     foreach my $arg (@{$options->{noop}}) {
 	info "The option --$arg is a no-op. It only exists for compatibility with some debootstrap wrappers.";
     }
@@ -2419,6 +2425,13 @@ then a single I<MIRROR> C<-> is added and thus the information of the desired
 suite has to come from standard input as part of a valid apt sources.list
 file.
 
+All status output is printed to standard error unless B<--logfile> is used to
+redirect it to a file or B<--quiet> or B<--silent> is used to suppress any
+output on standard error. Help and version information will be printed to
+standard error with the B<--help> and B<--version> options, respectively.
+Otherwise, an uncompressed tarball might be sent to standard output if
+I<TARGET> is C<-> or if no I<TARGET> was specified.
+
 =head1 OPTIONS
 
 Options are case insensitive. Short options may be bundled. Long options
@@ -2578,6 +2591,10 @@ In addition to the output produced by B<--verbose>, write detailed debugging
 information to standard error. Errors will print a backtrace. If used together
 with B<--quiet> or B<--verbose>, only the last option will take effect.
 
+=item B<--logfile>=I<filename>
+
+Instead of writing status information to standard error, write it into the
+file given by I<filename>.
 
 =back