remove libgcc1 for libc6 >= 2.30-2

The buildd variant of debootstrap will install libgcc-s1 *and* libgcc1
even though the former provides the latter. Remove the latter manually.

Since apt does not consider libgcc1 necessary, we have to download it
explicitly for debootstrap.

See Debian bug #953861

coverage.sh

@@ -131,6 +131,15 @@ tar --xattrs --xattrs-include='*' -C /tmp/debian-$dist-mm -xf /tmp/debian-$dist-
 mkdir /tmp/debian-$dist-debootstrap
 tar --xattrs --xattrs-include='*' -C /tmp/debian-$dist-debootstrap -xf "cache/debian-$dist-$variant.tar"
 
+# The buildd variant of debootstrap will install libgcc-s1 *and* libgcc1 even
+# though the former provides the latter. Remove the latter manually.
+if [ "$variant" = "buildd" ] \
+	&& chroot /tmp/debian-$dist-debootstrap dpkg -s libgcc-s1 2>&1 | grep --quiet '^Status: install ok installed$' \
+	&& chroot /tmp/debian-$dist-debootstrap dpkg -s libgcc1 2>&1 | grep --quiet '^Status: install ok installed$' \
+	&& dpkg --compare-versions "\$(chroot /tmp/debian-$dist-debootstrap dpkg -s libc6 | grep '^Version:' | cut -d ' ' -f 2)" ge 2.30-2; then
+	chroot /tmp/debian-$dist-debootstrap dpkg --remove libgcc1
+fi
+
 # diff cannot compare device nodes, so we use tar to do that for us and then
 # delete the directory
 tar -C /tmp/debian-$dist-debootstrap -cf dev1.tar ./dev

make_mirror.sh

@@ -239,7 +239,7 @@ END
 			--or --field=Priority important --or --field=Priority standard \
 			--or --field=Package build-essential \) )
 
-	pkgs="$(echo $pkgs) build-essential busybox gpg"
+	pkgs="$(echo $pkgs) build-essential busybox gpg libgcc1"
 
 	APT_CONFIG="$rootdir/etc/apt/apt.conf" apt-get --yes install $pkgs