release 1.3.5

Having world-writable apt.conf may be exploited by locals users to
execute arbitrary code in the context of the user running mmdebstrap.

CHANGELOG.md

@@ -1,3 +1,13 @@
+1.3.5 (2023-03-20)
+------------------
+
+ - bugfix release
+
+1.3.4 (2023-03-16)
+------------------
+
+ - more safeguards before automatically choosing unshare mode
+
 1.3.3 (2023-02-19)
 ------------------
 

README.md

@@ -152,13 +152,14 @@ Contributors
 ============
 
  - Johannes Schauer Marin Rodrigues (main author)
- - Gioele Barabucci
  - Helmut Grohne
+ - Gioele Barabucci
  - Benjamin Drung
  - Jochen Sprickerhof
  - Josh Triplett
  - Konstantin Demin
  - David Kalnischkies
+ - Jakub Wilk
  - Joe Groocock
  - Nicolas Vigier
  - Raul Tambre

coverage.sh

@@ -69,7 +69,7 @@ mirror="http://127.0.0.1/debian"
 
 export HAVE_QEMU HAVE_BINFMT RUN_MA_SAME_TESTS DEFAULT_DIST SOURCE_DATE_EPOCH CMD mirror
 
-./coverage.py
+./coverage.py "$@"
 
 if [ -e shared/cover_db.img ]; then
 	# produce report inside the VM to make sure that the versions match or

coverage.txt

@@ -283,10 +283,16 @@ Test: debootstrap-no-op-options
 Needs-Root: true
 
 Test: verbose
-Needs-Root: true
+Variants: - standard
+Skip-If:
+ variant == "-" and hostarch not in ["armel", "armhf", "mipsel"] # #1031276
+ variant == "standard" and hostarch in ["armel", "armhf", "mipsel"] # #1031276
 
 Test: debug
-Needs-Root: true
+Variants: - standard
+Skip-If:
+ variant == "-" and hostarch not in ["armel", "armhf", "mipsel"] # #1031276
+ variant == "standard" and hostarch in ["armel", "armhf", "mipsel"] # #1031276
 
 Test: quiet
 Needs-Root: true
@@ -396,6 +402,7 @@ Test: error-if-stdout-is-tty
 Test: variant-custom-timeout
 
 Test: include-deb-file
+Modes: root unshare fakechroot
 Needs-APT-Config: true
 
 Test: unshare-include-deb

hooks/file-mirror-automount/setup00.sh

@@ -14,6 +14,10 @@ env APT_CONFIG="$MMDEBSTRAP_APT_CONFIG" apt-get indextargets --no-release-info -
 	| sort -u \
 	| while read -r path; do
 		mkdir -p "$rootdir/run/mmdebstrap"
+		if [ ! -d "/$path" ]; then
+			echo "/$path is not an existing directory" >&2
+			continue
+		fi
 		case $MMDEBSTRAP_MODE in
 			root|unshare)
 				echo "bind-mounting /$path into the chroot" >&2
@@ -22,8 +26,8 @@ env APT_CONFIG="$MMDEBSTRAP_APT_CONFIG" apt-get indextargets --no-release-info -
 				;;
 			*)
 				echo "copying /$path into the chroot" >&2
-				mkdir -p "$rootdir/$(dirname "$path")"
-				cp -av "/$path" "$rootdir/$(dirname "$path")"
+				mkdir -p "$rootdir/$path"
+				"$MMDEBSTRAP_ARGV0" --hook-helper "$rootdir" "$MMDEBSTRAP_MODE" "$MMDEBSTRAP_HOOK" env "$MMDEBSTRAP_VERBOSITY" sync-in "/$path" "/$path" <&"$MMDEBSTRAP_HOOKSOCK" >&"$MMDEBSTRAP_HOOKSOCK"
 				;;
 		esac
 		printf '/%s\0' "$path" >> "$rootdir/run/mmdebstrap/file-mirror-automount"
@@ -47,6 +51,10 @@ for pkg in $MMDEBSTRAP_INCLUDE; do
 	fi
 	# make path absolute
 	pkg="$(realpath "$pkg")"
+	case "$pkg" in
+		/*) : ;;
+		*) echo "path for $pkg is not absolute" >&2; continue;;
+	esac
 	mkdir -p "$rootdir/run/mmdebstrap"
 	mkdir -p "$rootdir/$(dirname "$pkg")"
 	case $MMDEBSTRAP_MODE in
@@ -57,7 +65,7 @@ for pkg in $MMDEBSTRAP_INCLUDE; do
 			;;
 		*)
 			echo "copying $pkg into the chroot" >&2
-			cp -av "$pkg" "$rootdir/$pkg"
+			"$MMDEBSTRAP_ARGV0" --hook-helper "$rootdir" "$MMDEBSTRAP_MODE" "$MMDEBSTRAP_HOOK" env "$MMDEBSTRAP_VERBOSITY" upload "$pkg" "$pkg" <&"$MMDEBSTRAP_HOOKSOCK" >&"$MMDEBSTRAP_HOOKSOCK"
 			;;
 	esac
 	printf '/%s\0' "$pkg" >> "$rootdir/run/mmdebstrap/file-mirror-automount"

make_mirror.sh

@@ -20,7 +20,10 @@ deletecache() {
 		return 1
 	fi
 	# be very careful with removing the old directory
-	for dist in oldstable stable testing unstable; do
+	# experimental is pulled in with USE_HOST_APT_CONFIG=yes on debci
+	# when testing a package from experimental
+	for dist in oldstable stable testing unstable experimental; do
+		# deleting artifacts from test "debootstrap"
 		for variant in minbase buildd -; do
 			if [ -e "$dir/debian-$dist-$variant.tar" ]; then
 				rm "$dir/debian-$dist-$variant.tar"
@@ -28,6 +31,18 @@ deletecache() {
 				echo "does not exist: $dir/debian-$dist-$variant.tar" >&2
 			fi
 		done
+		# deleting artifacts from test "mmdebstrap"
+		for variant in essential apt minbase buildd - standard; do
+			for format in tar ext2 squashfs; do
+				if [ -e "$dir/mmdebstrap-$dist-$variant.$format" ]; then
+					# attempt to delete for all dists because DEFAULT_DIST might've been different the last time
+					rm "$dir/mmdebstrap-$dist-$variant.$format"
+				elif [ "$dist" = "$DEFAULT_DIST" ]; then
+					# only warn about non-existance when it's expected to exist
+					echo "does not exist: $dir/mmdebstrap-$dist-$variant.$format" >&2
+				fi
+			done
+		done
 		if [ -e "$dir/debian/dists/$dist" ]; then
 			rm --one-file-system --recursive "$dir/debian/dists/$dist"
 		else
@@ -63,11 +78,16 @@ deletecache() {
 			rm --one-file-system "$f"
 		fi
 	done
-	if [ -e "$dir/debian/pool/main" ]; then
-		rm --one-file-system --recursive "$dir/debian/pool/main"
+	# on i386 and amd64, the intel-microcode and amd64-microcode packages
+	# from non-free-firwame get pulled in because they are
+	# priority:standard with USE_HOST_APT_CONFIG=yes
+	for c in main non-free-firmware; do
+		if [ -e "$dir/debian/pool/$c" ]; then
+			rm --one-file-system --recursive "$dir/debian/pool/$c"
 		else
-		echo "does not exist: $dir/debian/pool/main" >&2
+			echo "does not exist: $dir/debian/pool/$c" >&2
 		fi
+	done
 	if [ -e "$dir/debian-security/pool/updates/main" ]; then
 		rm --one-file-system --recursive "$dir/debian-security/pool/updates/main"
 	else

mmdebstrap

@@ -23,7 +23,7 @@
 use strict;
 use warnings;
 
-our $VERSION = '1.3.3';
+our $VERSION = '1.3.5';
 
 use English;
 use Getopt::Long;
@@ -305,14 +305,18 @@ sub shellescape {
 
 sub test_unshare_userns {
     my $verbose = shift;
-    my $unshare_fail = shift;
-    if ($EFFECTIVE_USER_ID == 0) {
-        my $msg = "cannot unshare user namespace when executing as root";
+
+    local *maybe_error = sub {
+        my $msg = shift;
         if ($verbose) {
-            warning $msg;
+            error $msg;
         } else {
             debug $msg;
         }
+    };
+
+    if ($EFFECTIVE_USER_ID == 0) {
+        maybe_error("cannot unshare user namespace when executing as root");
         return 0;
     }
     # arguments to syscalls have to be stored in their own variable or
@@ -326,12 +330,7 @@ sub test_unshare_userns {
         if ($ret == 0) {
             exit 0;
         } else {
-            my $msg = "unshare syscall failed: $!";
-            if ($verbose) {
-                warning $msg;
-            } else {
-                debug $msg;
-            }
+            maybe_error("unshare syscall failed: $!");
             exit 1;
         }
     }
@@ -344,120 +343,140 @@ sub test_unshare_userns {
     system "newuidmap 2>/dev/null";
     if (($? >> 8) != 1) {
         if (($? >> 8) == 127) {
-            my $msg = "cannot find newuidmap";
-            if ($verbose) {
-                if ($unshare_fail) {
-                    error $msg;
+            maybe_error("cannot find newuidmap");
         } else {
-                    warning $msg;
-                }
-            } else {
-                debug $msg;
-            }
-        } else {
-            my $msg = "newuidmap returned unknown exit status: $?";
-            if ($verbose) {
-                warning $msg;
-            } else {
-                debug $msg;
-            }
+            maybe_error("newuidmap returned unknown exit status: $?");
         }
         return 0;
     }
     system "newgidmap 2>/dev/null";
     if (($? >> 8) != 1) {
         if (($? >> 8) == 127) {
-            my $msg = "cannot find newgidmap";
-            if ($verbose) {
-                warning $msg;
+            maybe_error("cannot find newgidmap");
         } else {
-                debug $msg;
+            maybe_error("newgidmap returned unknown exit status: $?");
         }
+        return 0;
+    }
+    my @idmap = read_subuid_subgid($verbose);
+    if (scalar @idmap == 0) {
+        maybe_error("failed to parse /etc/subuid and /etc/subgid");
+        return 0;
+    }
+    # too much can go wrong when doing the dance required to unsharing the user
+    # namespace, so instead of adding more complexity to support maybe_error()
+    # to a function that is already too complex, we use eval()
+    eval {
+        $pid = get_unshare_cmd(
+            sub {
+                if ($EFFECTIVE_USER_ID == 0) {
+                    exit 0;
                 } else {
-            my $msg = "newgidmap returned unknown exit status: $?";
-            if ($verbose) {
-                warning $msg;
-            } else {
-                debug $msg;
+                    exit 1;
                 }
+            },
+            \@idmap
+        );
+        waitpid $pid, 0;
+        if ($? != 0) {
+            maybe_error("failed to unshare the user namespace");
+            return 0;
         }
+    };
+    if ($@) {
+        maybe_error($@);
         return 0;
     }
     return 1;
 }
 
-sub read_subuid_subgid() {
+sub read_subuid_subgid {
+    my $verbose  = shift;
+    my @result   = ();
     my $username = getpwuid $REAL_USER_ID;
     my ($subid, $num_subid, $fh, $n);
-    my @result = ();
 
+    local *maybe_warn = sub {
+        my $msg = shift;
+        if ($verbose) {
+            warning $msg;
+        } else {
+            debug $msg;
+        }
+    };
     if (!-e "/etc/subuid") {
-        warning "/etc/subuid doesn't exist";
+        maybe_warn("/etc/subuid doesn't exist");
         return;
     }
     if (!-r "/etc/subuid") {
-        warning "/etc/subuid is not readable";
+        maybe_warn("/etc/subuid is not readable");
         return;
     }
 
     open $fh, "<", "/etc/subuid"
-      or error "cannot open /etc/subuid for reading: $!";
+      or maybe_warn("cannot open /etc/subuid for reading: $!");
+    if (!$fh) {
+        return;
+    }
     while (my $line = <$fh>) {
         ($n, $subid, $num_subid) = split(/:/, $line, 3);
         last if ($n eq $username);
     }
     close $fh;
     if (!length $subid) {
-        warning "/etc/subuid is empty";
+        maybe_warn("/etc/subuid is empty");
         return;
     }
     if ($n ne $username) {
-        warning "no entry in /etc/subuid for $username";
+        maybe_warn("no entry in /etc/subuid for $username");
         return;
     }
     push @result, ["u", 0, $subid, $num_subid];
 
     if (scalar(@result) < 1) {
-        warning "/etc/subuid does not contain an entry for $username";
+        maybe_warn("/etc/subuid does not contain an entry for $username");
         return;
     }
     if (scalar(@result) > 1) {
-        warning "/etc/subuid contains multiple entries for $username";
+        maybe_warn("/etc/subuid contains multiple entries for $username");
         return;
     }
 
     if (!-e "/etc/subgid") {
-        warning "/etc/subgid doesn't exist";
+        maybe_warn("/etc/subgid doesn't exist");
         return;
     }
     if (!-r "/etc/subgid") {
-        warning "/etc/subgid is not readable";
+        maybe_warn("/etc/subgid is not readable");
         return;
     }
 
     open $fh, "<", "/etc/subgid"
-      or error "cannot open /etc/subgid for reading: $!";
+      or maybe_warn("cannot open /etc/subgid for reading: $!");
+    if (!$fh) {
+        return;
+    }
     while (my $line = <$fh>) {
         ($n, $subid, $num_subid) = split(/:/, $line, 3);
         last if ($n eq $username);
     }
     close $fh;
     if (!length $subid) {
-        warning "/etc/subgid is empty";
+        maybe_warn("/etc/subgid is empty");
         return;
     }
     if ($n ne $username) {
-        warning "no entry in /etc/subgid for $username";
+        maybe_warn("no entry in /etc/subgid for $username");
         return;
     }
     push @result, ["g", 0, $subid, $num_subid];
 
     if (scalar(@result) < 2) {
-        warning "/etc/subgid does not contain an entry for $username";
+        maybe_warn("/etc/subgid does not contain an entry for $username");
         return;
     }
     if (scalar(@result) > 2) {
-        warning "/etc/subgid contains multiple entries for $username";
+        maybe_warn("/etc/subgid contains multiple entries for $username");
         return;
     }
 
@@ -1594,6 +1613,9 @@ sub run_hooks {
     if (length $ENV{APT_CONFIG}) {
         push @env_opts, "MMDEBSTRAP_APT_CONFIG=$ENV{APT_CONFIG}";
     }
+    # I hook script that wants to call mmdebstrap with --hook-helper needs to
+    # know how mmdebstrap was executed
+    push @env_opts, "MMDEBSTRAP_ARGV0=$PROGRAM_NAME";
     # Storing the mode is important for hook scripts to potentially change
     # their behavior depending on the mode. It's also important for when the
     # hook wants to use the mmdebstrap --hook-helper.
@@ -1801,6 +1823,25 @@ sub setup {
 
     run_hooks('setup', $options);
 
+    # apt runs dpkg from inside the chroot and directly passes the filename to
+    # dpkg. Hence, the included files on the outside must be present under the
+    # same path on the inside. If they are not, dpkg cannot find them.
+    if (scalar(grep { /^\// } @{ $options->{include} }) > 0) {
+        my $ret = 0;
+        foreach my $f (grep { /^\// } @{ $options->{include} }) {
+            next if -e "$options->{root}/$f";
+            warning
+              "path given via --include is not present inside the chroot: $f";
+            $ret = 1;
+        }
+        if ($ret != 0) {
+            warning("apt runs chrooted dpkg which needs access to the "
+                  . "package paths given via --include inside the chroot.");
+            warning "maybe try running mmdebstrap with "
+              . "--hook-dir=/usr/share/mmdebstrap/hooks/file-mirror-automount";
+        }
+    }
+
     if (any { $_ eq 'update' } @{ $options->{skip} }) {
         info "skipping update as requested";
     } else {
@@ -2246,7 +2287,7 @@ sub run_setup() {
     # we have to make the config file world readable so that a possible
     # /usr/lib/apt/solvers/apt process which is run by the _apt user is also
     # able to read it
-    chmod 0666, "$tmpfile" or error "cannot chmod $tmpfile: $!";
+    chmod 0644, "$tmpfile" or error "cannot chmod $tmpfile: $!";
     if ($verbosity_level >= 3) {
         0 == system('apt-get', '--version')
           or error "apt-get --version failed: $?";
@@ -4348,12 +4389,12 @@ sub main() {
     # lxc-usernsexec -- lxc-unshare -s 'MOUNT|PID|UTSNAME|IPC' ...
     # but without needing lxc
     if (scalar @ARGV >= 1 && $ARGV[0] eq "--unshare-helper") {
-        if ($EFFECTIVE_USER_ID != 0 && !test_unshare_userns(1)) {
-            exit 1;
+        if ($EFFECTIVE_USER_ID != 0) {
+            test_unshare_userns(1);
         }
         my @idmap = ();
         if ($EFFECTIVE_USER_ID != 0) {
-            @idmap = read_subuid_subgid;
+            @idmap = read_subuid_subgid 1;
         }
         my $pid = get_unshare_cmd(
             sub {
@@ -4423,10 +4464,8 @@ sub main() {
             my ($opt_name, $opt_value) = @_;
             my $sanitize_path = sub {
                 my $pkg = shift;
-                $pkg = abs_path($pkg);
-                if (!defined $pkg) {
-                    error "cannot resolve absolute path of $pkg: $!";
-                }
+                $pkg = abs_path($pkg)
+                  // error "cannot resolve absolute path of $pkg: $!";
                 if ($pkg !~ /^\//) {
                     error "absolute path of $pkg doesn't start with a slash";
                 }
@@ -4781,7 +4820,8 @@ sub main() {
             }
             exec 'fakechroot', 'fakeroot', @prefix, $PROGRAM_NAME, @ARGVORIG;
         } else {
-            error "unable to pick chroot mode automatically";
+            error(  "unable to pick chroot mode automatically (use --mode for "
+                  . "manual selection)");
         }
         info "automatically chosen mode: $options->{mode}";
     } elsif ($options->{mode} eq 'root') {
@@ -4816,26 +4856,8 @@ sub main() {
         }
         # ...or we are not root and then we need to be able to unshare the user
         # namespace.
-        if ($EFFECTIVE_USER_ID != 0 && !test_unshare_userns(1, 1)) {
-            my $procfile = '/proc/sys/kernel/unprivileged_userns_clone';
-            open(my $fh, '<', $procfile)
-              or error "failed to open $procfile: $!";
-            chomp(
-                my $content = do { local $/; <$fh> }
-            );
-            close($fh);
-            if ($content ne "1") {
-                info "/proc/sys/kernel/unprivileged_userns_clone is set to"
-                  . " $content";
-                info "Try running:";
-                info "  sudo sysctl -w kernel.unprivileged_userns_clone=1";
-                info "or permanently enable unprivileged usernamespaces by"
-                  . " putting the setting into /etc/sysctl.d/";
-                info "THIS SETTING HAS SECURITY IMPLICATIONS!";
-                info "Refer to https://bugs.debian.org/cgi-bin/"
-                  . "bugreport.cgi?bug=898446";
-            }
-            exit 1;
+        if ($EFFECTIVE_USER_ID != 0) {
+            test_unshare_userns(1);
         }
     } elsif ($options->{mode} eq 'chrootless') {
         if ($EFFECTIVE_USER_ID == 0) {
@@ -5171,12 +5193,14 @@ sub main() {
                 my $keyring
                   = get_keyring_by_suite($options->{suite}, \%suite_by_vendor);
                 if (!defined $keyring) {
+                    debug "get_keyring_by_suite() cannot find keyring";
                     return '';
                 }
 
                 # we can only check if we need the signed-by entry if we u
                 # automatically chosen keyring exists
                 if (!defined $keyring || !-e $keyring) {
+                    debug "found keyring does not exist";
                     return '';
                 }
 
@@ -5221,7 +5245,7 @@ sub main() {
                 # find all the fingerprints of the keys apt currently
                 # knows about
                 my @keyrings = ();
-                opendir my $dh, "$options->{apttrustedparts}"
+                opendir my $dh, $options->{apttrustedparts}
                   or error "cannot read $options->{apttrustedparts}";
                 while (my $filename = readdir $dh) {
                     if ($filename !~ /\.(asc|gpg)$/) {
@@ -5230,7 +5254,7 @@ sub main() {
                     $filename = "$options->{apttrustedparts}/$filename";
                     # skip empty keyrings
                     -s "$filename" || next;
-                    push @keyrings, "$filename";
+                    push @keyrings, $filename;
                 }
                 closedir $dh;
                 if (-s $options->{apttrusted}) {
@@ -5238,6 +5262,7 @@ sub main() {
                 }
                 my @aptfingerprints = ();
                 if (scalar @keyrings == 0) {
+                    debug "no keyring is trusted by apt";
                     return " [signed-by=\"$keyring\"]";
                 }
                 info "finding correct signed-by value...";
@@ -5261,6 +5286,7 @@ sub main() {
                 }
                 print_progress("done");
                 if (scalar @aptfingerprints == 0) {
+                    debug "no fingerprints found";
                     return " [signed-by=\"$keyring\"]";
                 }
                 # check if all fingerprints from the keyring that we guessed
@@ -5277,6 +5303,7 @@ sub main() {
                         # if this fingerprint is not known by apt, then we need
                         #to add the signed-by option
                         if (none { $_ eq $1 } @aptfingerprints) {
+                            debug "fingerprint $1 is not trusted by apt";
                             return " [signed-by=\"$keyring\"]";
                         }
                     }
@@ -5665,7 +5692,7 @@ sub main() {
     # for unshare mode the rootfs directory has to have appropriate
     # permissions
     if ($EFFECTIVE_USER_ID != 0 and $options->{mode} eq 'unshare') {
-        @idmap = read_subuid_subgid;
+        @idmap = read_subuid_subgid 1;
         # sanity check
         if (   scalar(@idmap) != 2
             || $idmap[0][0] ne 'u'
@@ -5712,9 +5739,9 @@ sub main() {
         );
         waitpid $pid, 0;
         if ($? != 0) {
-            warning "no read access for some packages for the unshared user";
-            warning "maybe try running mmdebstrap with "
-              . "--hook-dir=/usr/share/mmdebstrap/hooks/file-mirror-automount";
+            warning("apt on the outside is run as the unshared user and "
+                  . "needs read access to packages outside the chroot given "
+                  . "via --include");
         }
     }
 
@@ -6450,8 +6477,9 @@ by this option will be the only ones that get either extracted or installed by
 dpkg, respectively.  For all other variants, apt is used to install the
 additional packages. Package names are directly passed to apt and thus, you
 can use apt features like C<pkg/suite>, C<pkg=version>, C<pkg->, use a glob or
-regex for C<pkg>, use apt patterns or pass a path to a .deb package file. See
-apt(8) for the supported syntax.
+regex for C<pkg>, use apt patterns or pass a path to a .deb package file (see
+below for notes concerning passing the path to a .deb package file in
+B<unshare> mode). See apt(8) for the supported syntax.
 
 The option can be specified multiple times and the packages are concatenated in
 the order in which they are given on the command line. If later list items are
@@ -6479,6 +6507,22 @@ apt. To add more packages, use multiple B<--include> options. To disable this
 detection of patterns and paths, start the argument to B<--include> with a
 comma or whitespace.
 
+If you pass the path to a .deb package file using B<--include>, B<mmdebstrap>
+will ensure that the path exists. If the path is a relative path, it will
+internally by converted to an absolute path. Since apt (outside the chroot)
+passes paths to dpkg (on the inside) verbatim, you have to make the .deb
+package available under the same path inside the chroot as well or otherwise
+dpkg inside the chroot will be unable to access it. This can be achieved using
+a setup-hook. A hook that automatically makes the contents of C<file://>
+mirrors as well as .deb packages given with B<--include> available inside the
+chroot is provided by B<mmdebstrap> as
+B<--hook-dir=/usr/share/mmdebstrap/hooks/file-mirror-automount>. This hook
+takes care of copying all relevant file to their correct locations and cleans
+up those files at the end. In B<unshare> mode, the .deb package paths have to
+be accessible by the unshared user as well. This means that the package itself
+likely must be made world-readable and all directory components on the path to
+it world-executable.
+
 =item B<--components>=I<comp1>[,I<comp2>,...]
 
 Comma or whitespace separated list of components like main, contrib, non-free
@@ -6668,9 +6712,9 @@ decides which way this is achieved.
 
 This mode automatically selects a fitting mode. If the effective user id is the
 one of the superuser, then the B<sudo> mode is chosen. Otherwise, the
-B<unshare> mode is picked if the system has the sysctl
-C<kernel.unprivileged_userns_clone> set to C<1>. Should that not be the case
-and if the fakechroot binary exists, the B<fakechroot> mode is chosen.
+B<unshare> mode is picked if F</etc/subuid> and F</etc/subgid> are set up
+correctly. Should that not be the case and if the fakechroot binary exists, the
+B<fakechroot> mode is chosen.
 
 =item B<sudo>, B<root>
 
@@ -6935,11 +6979,13 @@ C<MMDEBSTRAP_APT_CONFIG> environment variable. All environment variables set by
 the user are preserved, except for C<TMPDIR> which is cleared. See section
 B<TMPDIR>. Furthermore, C<MMDEBSTRAP_MODE> will store the mode set by
 B<--mode>, C<MMDEBSTRAP_HOOK> stores which hook is currently run (setup,
-extract, essential, customize) and C<MMDEBSTRAP_VERBOSITY> stores the numerical
-verbosity level (0 for no output, 1 for normal, 2 for verbose and 3 for debug
-output). The C<MMDEBSTRAP_INCLUDE> variable stores the list of packages, apt
-patterns or file paths given by the B<--include> option, separated by a comma
-and with commas and percent signs in the option values urlencoded.
+extract, essential, customize), C<MMDEBSTRAP_ARGV0> stores the name of the
+binary with which B<mmdebstrap> was executed and C<MMDEBSTRAP_VERBOSITY> stores
+the numerical verbosity level (0 for no output, 1 for normal, 2 for verbose and
+3 for debug output). The C<MMDEBSTRAP_INCLUDE> variable stores the list of
+packages, apt patterns or file paths given by the B<--include> option,
+separated by a comma and with commas and percent signs in the option values
+urlencoded.
 
 In special hooks, the paths inside the chroot are relative to the root
 directory of the chroot.  The path on the outside is relative to current

tests/ascii-armored-keys

@@ -5,14 +5,19 @@ if [ ! -e /mmdebstrap-testenv ]; then
 	echo "this test modifies the system and should only be run inside a container" >&2
 	exit 1
 fi
+for f in /etc/apt/trusted.gpg.d/*.gpg /etc/apt/trusted.gpg.d/*.asc; do
+	[ -e "$f" ] || continue
+	rm "$f"
+done
+rmdir /etc/apt/trusted.gpg.d
+mkdir /etc/apt/trusted.gpg.d
 for f in /usr/share/keyrings/*.gpg; do
 	name=$(basename "$f" .gpg)
 	gpg --enarmor < "/usr/share/keyrings/$name.gpg" \
 		| sed 's/ PGP ARMORED FILE/ PGP PUBLIC KEY BLOCK/;/^Comment: /d' \
 		> "/etc/apt/trusted.gpg.d/$name.asc"
+	rm "/usr/share/keyrings/$name.gpg"
 done
-rm /etc/apt/trusted.gpg.d/*.gpg
-rm /usr/share/keyrings/*.gpg
 {{ CMD }} --mode=root --variant=apt {{ DIST }} /tmp/debian-chroot.tar {{ MIRROR }}
 tar -tf /tmp/debian-chroot.tar | sort | diff -u tar1.txt -
 rm -r /tmp/debian-chroot.tar

tests/check-for-bit-by-bit-identical-format-output

@@ -5,6 +5,10 @@ export SOURCE_DATE_EPOCH={{ SOURCE_DATE_EPOCH }}
 
 trap "rm -f /tmp/debian-chroot-{{ MODE }}.{{ FORMAT }}" EXIT INT TERM
 
+case {{ MODE }} in unshare|fakechroot) : ;; *) exit 1;; esac
+
+prefix=
+if [ "$(id -u)" -eq 0 ] && [ "{{ MODE }}" != "root" ] && [ "{{ MODE }}" != "auto" ]; then
 	if ! id "${SUDO_USER:-user}" >/dev/null 2>&1; then
 		if [ ! -e /mmdebstrap-testenv ]; then
 			echo "this test modifies the system and should only be run inside a container" >&2
@@ -12,7 +16,10 @@ if ! id "${SUDO_USER:-user}" >/dev/null 2>&1; then
 		fi
 		useradd --home-dir "/home/${SUDO_USER:-user}" --create-home "${SUDO_USER:-user}"
 	fi
-runuser -u "${SUDO_USER:-user}" -- {{ CMD }} --mode={{ MODE }} --variant={{ VARIANT }} {{ DIST }} /tmp/debian-chroot-{{ MODE }}.{{ FORMAT }} {{ MIRROR }}
+	prefix="runuser -u ${SUDO_USER:-user} --"
+fi
+
+$prefix {{ CMD }} --mode={{ MODE }} --variant={{ VARIANT }} {{ DIST }} /tmp/debian-chroot-{{ MODE }}.{{ FORMAT }} {{ MIRROR }}
 cmp ./cache/mmdebstrap-{{ DIST }}-{{ VARIANT }}.{{ FORMAT }} /tmp/debian-chroot-{{ MODE }}.{{ FORMAT }} \
 	|| diffoscope ./cache/mmdebstrap-{{ DIST }}-{{ VARIANT }}.{{ FORMAT }} /tmp/debian-chroot-{{ MODE }}.{{ FORMAT }}
 

tests/debug

@@ -1,6 +1,17 @@
 #!/bin/sh
 set -eu
 export LC_ALL=C.UTF-8
-{{ CMD }} --mode=root --variant=apt --debug {{ DIST }} /tmp/debian-chroot {{ MIRROR }}
-tar -C /tmp/debian-chroot --one-file-system -c . | tar -t | sort | diff -u tar1.txt -
-rm -r /tmp/debian-chroot
+export SOURCE_DATE_EPOCH={{ SOURCE_DATE_EPOCH }}
+
+trap "rm -f /tmp/debian-chroot.tar" EXIT INT TERM
+
+# we use variant standard in verbose mode to see the maximum number of packages
+# that was chosen in case of USE_HOST_APT_CONFIG=yes
+# we use variant important on arches where variant standard is not bit-by-bit
+# reproducible due to #1031276
+case {{ VARIANT }} in standard|-) : ;; *) exit 1;; esac
+
+{{ CMD }} --variant={{ VARIANT }} --debug {{ DIST }} /tmp/debian-chroot.tar {{ MIRROR }}
+
+cmp ./cache/mmdebstrap-{{ DIST }}-{{ VARIANT }}.tar /tmp/debian-chroot.tar \
+	|| diffoscope ./cache/mmdebstrap-{{ DIST }}-{{ VARIANT }}.tar /tmp/debian-chroot.tar

tests/fail-without-etc-subuid

@@ -13,4 +13,4 @@ if [ "$ret" = 0 ]; then
 	echo expected failure but got exit $ret >&2
 	exit 1
 fi
-rm -r /tmp/debian-chroot
+[ ! -e /tmp/debian-chroot ]

tests/fail-without-username-in-etc-subuid

@@ -14,4 +14,4 @@ if [ "$ret" = 0 ]; then
 	echo expected failure but got exit $ret >&2
 	exit 1
 fi
-rm -r /tmp/debian-chroot
+[ ! -e /tmp/debian-chroot ]

tests/include-deb-file

@@ -5,6 +5,18 @@ export LC_ALL=C.UTF-8
 
 trap "rm -rf /tmp/dummypkg.deb /tmp/dummypkg" EXIT INT TERM
 
+prefix=
+if [ "$(id -u)" -eq 0 ] && [ "{{ MODE }}" != "root" ] && [ "{{ MODE }}" != "auto" ]; then
+	if ! id "${SUDO_USER:-user}" >/dev/null 2>&1; then
+		if [ ! -e /mmdebstrap-testenv ]; then
+			echo "this test modifies the system and should only be run inside a container" >&2
+			exit 1
+		fi
+		useradd --home-dir "/home/${SUDO_USER:-user}" --create-home "${SUDO_USER:-user}"
+	fi
+	prefix="runuser -u ${SUDO_USER:-user} --"
+fi
+
 # instead of obtaining a .deb from our cache, we create a new package because
 # otherwise apt might decide to download the package with the same name and
 # version from the cache instead of using the local .deb
@@ -22,7 +34,7 @@ Description: dummypkg
 END
 dpkg-deb --build "/tmp/dummypkg" "/tmp/dummypkg.deb"
 
-{{ CMD }} --variant=apt --include="/tmp/dummypkg.deb" \
+$prefix {{ CMD }} --mode={{ MODE }} --variant=apt --include="/tmp/dummypkg.deb" \
 	--hook-dir=./hooks/file-mirror-automount \
 	--customize-hook='chroot "$1" dpkg-query -W -f="\${Status}\n" dummypkg | grep "^install ok installed$"' \
 	{{ DIST }} /dev/null {{ MIRROR }}

tests/keyring

@@ -5,7 +5,12 @@ if [ ! -e /mmdebstrap-testenv ]; then
 	echo "this test modifies the system and should only be run inside a container" >&2
 	exit 1
 fi
-rm /etc/apt/trusted.gpg.d/*.gpg
+for f in /etc/apt/trusted.gpg.d/*.gpg /etc/apt/trusted.gpg.d/*.asc; do
+	[ -e "$f" ] || continue
+	rm "$f"
+done
+rmdir /etc/apt/trusted.gpg.d
+mkdir /etc/apt/trusted.gpg.d
 {{ CMD }} --mode=root --variant=apt --keyring=/usr/share/keyrings/debian-archive-keyring.gpg --keyring=/usr/share/keyrings/ {{ DIST }} /tmp/debian-chroot "deb {{ MIRROR }} {{ DIST }} main"
 # make sure that no [signedby=...] managed to make it into the sources.list
 echo "deb {{ MIRROR }} {{ DIST }} main" | cmp /tmp/debian-chroot/etc/apt/sources.list -

tests/multiple-include

@@ -12,14 +12,10 @@ rm /tmp/debian-chroot/etc/timezone
 rm -r /tmp/debian-chroot/usr/share/doc/tzdata
 rm -r /tmp/debian-chroot/usr/share/zoneinfo
 rm /tmp/debian-chroot/var/lib/apt/extended_states
-rm /tmp/debian-chroot/var/lib/dpkg/info/doc-debian.list
-rm /tmp/debian-chroot/var/lib/dpkg/info/doc-debian.md5sums
-rm /tmp/debian-chroot/var/lib/dpkg/info/tzdata.list
-rm /tmp/debian-chroot/var/lib/dpkg/info/tzdata.md5sums
-rm /tmp/debian-chroot/var/lib/dpkg/info/tzdata.config
-rm /tmp/debian-chroot/var/lib/dpkg/info/tzdata.postinst
-rm /tmp/debian-chroot/var/lib/dpkg/info/tzdata.postrm
-rm /tmp/debian-chroot/var/lib/dpkg/info/tzdata.templates
-rm /tmp/debian-chroot/var/lib/dpkg/info/tzdata.preinst
-rm /tmp/debian-chroot/var/lib/dpkg/info/tzdata.prerm
+for p in doc-debian tzdata; do
+	for f in list md5sums config postinst postrm templates preinst prerm; do
+		[ -e "/tmp/debian-chroot/var/lib/dpkg/info/$p.$f" ] || continue
+		rm "/tmp/debian-chroot/var/lib/dpkg/info/$p.$f"
+	done
+done
 tar -C /tmp/debian-chroot --one-file-system -c . | tar -t | sort | diff -u tar1.txt -

tests/signed-by-without-host-keys

@@ -5,7 +5,12 @@ if [ ! -e /mmdebstrap-testenv ]; then
 	echo "this test modifies the system and should only be run inside a container" >&2
 	exit 1
 fi
-rm /etc/apt/trusted.gpg.d/*.gpg
+for f in /etc/apt/trusted.gpg.d/*.gpg /etc/apt/trusted.gpg.d/*.asc; do
+	[ -e "$f" ] || continue
+	rm "$f"
+done
+rmdir /etc/apt/trusted.gpg.d
+mkdir /etc/apt/trusted.gpg.d
 {{ CMD }} --mode=root --variant=apt {{ DIST }} /tmp/debian-chroot {{ MIRROR }}
 printf 'deb [signed-by="/usr/share/keyrings/debian-archive-keyring.gpg"] {{ MIRROR }} {{ DIST }} main\n' | cmp /tmp/debian-chroot/etc/apt/sources.list -
 tar -C /tmp/debian-chroot --one-file-system -c . | tar -t | sort | diff -u tar1.txt -

tests/verbose

@@ -1,6 +1,17 @@
 #!/bin/sh
 set -eu
 export LC_ALL=C.UTF-8
-{{ CMD }} --mode=root --variant=apt --verbose {{ DIST }} /tmp/debian-chroot {{ MIRROR }}
-tar -C /tmp/debian-chroot --one-file-system -c . | tar -t | sort | diff -u tar1.txt -
-rm -r /tmp/debian-chroot
+export SOURCE_DATE_EPOCH={{ SOURCE_DATE_EPOCH }}
+
+trap "rm -f /tmp/debian-chroot.tar" EXIT INT TERM
+
+# we use variant standard in verbose mode to see the maximum number of packages
+# that was chosen in case of USE_HOST_APT_CONFIG=yes
+# we use variant important on arches where variant standard is not bit-by-bit
+# reproducible due to #1031276
+case {{ VARIANT }} in standard|-) : ;; *) exit 1;; esac
+
+{{ CMD }} --variant={{ VARIANT }} --verbose {{ DIST }} /tmp/debian-chroot.tar {{ MIRROR }}
+
+cmp ./cache/mmdebstrap-{{ DIST }}-{{ VARIANT }}.tar /tmp/debian-chroot.tar \
+	|| diffoscope ./cache/mmdebstrap-{{ DIST }}-{{ VARIANT }}.tar /tmp/debian-chroot.tar