it's possible that apt is already downloaded at the time where we want to install it

coverage.sh

@@ -52,7 +52,7 @@ if [ ! -e shared/mmdebstrap ] || [ mmdebstrap -nt shared/mmdebstrap ]; then
 fi
 
 starttime=
-total=103
+total=104
 i=1
 
 print_header() {
@@ -1143,6 +1143,23 @@ else
 	echo "HAVE_QEMU != yes -- Skipping test..."
 fi
 
+print_header "mode=$defaultmode,variant=essential: test not having to installing apt with --include"
+cat << END > shared/test.sh
+#!/bin/sh
+set -eu
+export LC_ALL=C.UTF-8
+$CMD --mode=$defaultmode --variant=essential --include=apt --setup-hook="apt-get update" --setup-hook="apt-get --yes -oApt::Get::Download-Only=true install apt" $DEFAULT_DIST /tmp/debian-chroot.tar $mirror
+tar -tf /tmp/debian-chroot.tar | sort | diff -u tar1.txt -
+rm /tmp/debian-chroot.tar
+END
+if [ "$HAVE_QEMU" = "yes" ]; then
+	./run_qemu.sh
+elif [ "$defaultmode" = "root" ]; then
+	./run_null.sh SUDO
+else
+	./run_null.sh
+fi
+
 # test all variants
 
 for variant in essential apt required minbase buildd important debootstrap - standard; do

mmdebstrap

@@ -1695,18 +1695,19 @@ sub setup {
 		    }
 		    close $dh;
 		    if (scalar @debs_to_install == 0) {
-			error "nothing got downloaded";
-		    }
-		    # we need --force-depends because dpkg does not take Pre-Depends
-		    # into account and thus doesn't install them in the right order
-		    info 'installing ' . (join ', ', keys %pkgs_to_install_from_outside) . "...";
-		    run_dpkg_progress({
-			    ARGV => [@chrootcmd, 'env', '--unset=TMPDIR',
-				'dpkg',  '--install', '--force-depends'],
-			    PKGS => \@debs_to_install,
-			});
-		    foreach my $deb (@debs_to_install) {
-			unlink "$options->{root}/$deb" or error "cannot unlink $deb: $!";
+			warning "nothing got downloaded -- maybe the packages were already installed?";
+		    } else {
+			# we need --force-depends because dpkg does not take Pre-Depends
+			# into account and thus doesn't install them in the right order
+			info 'installing ' . (join ', ', keys %pkgs_to_install_from_outside) . "...";
+			run_dpkg_progress({
+				ARGV => [@chrootcmd, 'env', '--unset=TMPDIR',
+				    'dpkg',  '--install', '--force-depends'],
+				PKGS => \@debs_to_install,
+			    });
+			foreach my $deb (@debs_to_install) {
+			    unlink "$options->{root}/$deb" or error "cannot unlink $deb: $!";
+			}
 		    }
 		}