1 files changed, 44 insertions, 0 deletions
diff --git a/hooks/copy-host-apt-sources-and-preferences/customize00.pl b/hooks/copy-host-apt-sources-and-preferences/customize00.pl
new file mode 100755
index 0000000..53f6059
--- /dev/null
+++ b/hooks/copy-host-apt-sources-and-preferences/customize00.pl
@@ -0,0 +1,44 @@
+#!/usr/bin/perl
+#
+# This script makes sure that all packages that are installed both locally as
+# well as inside the chroot have the same version.
+#
+# It is implemented in Perl because there are no associative arrays in POSIX
+# shell.
+
+use strict;
+use warnings;
+
+sub get_pkgs {
+    my $root = shift;
+    my %pkgs = ();
+    open(my $fh, '-|', 'dpkg-query', "--root=$root", '--showformat',
+        '${binary:Package}=${Version}\n', '--show')
+      // die "cannot exec dpkg-query";
+    while (my $line = <$fh>) {
+        my ($pkg, $ver) = split(/=/, $line, 2);
+        $pkgs{$pkg} = $ver;
+    }
+    close $fh;
+    if ($? != 0) { die "failed to run dpkg-query" }
+    return %pkgs;
+}
+
+my %pkgs_local  = get_pkgs('/');
+my %pkgs_chroot = get_pkgs($ARGV[0]);
+
+my @diff = ();
+foreach my $pkg (keys %pkgs_chroot) {
+    next unless exists $pkgs_local{$pkg};
+    if ($pkgs_local{$pkg} ne $pkgs_chroot{$pkg}) {
+        push @diff, $pkg;
+    }
+}
+
+if (scalar @diff > 0) {
+    print STDERR "E: packages from the host and the chroot differ:\n";
+    foreach my $pkg (@diff) {
+	print STDERR "E: $pkg $pkgs_local{$pkg} $pkgs_chroot{$pkg}\n";
+    }
+    exit 1;
+}