Anticipate arch-test not being installed and only check if chroot architecture is unequal host's architecture

mmdebstrap

@@ -954,6 +954,7 @@ sub main() {
     $options->{nativearch} = $nativearch;
     $options->{foreignarchs} = \@foreignarchs;
 
+    {
 	my $deb2qemu = {
 	    alpha => 'alpha',
 	    amd64 => 'x86_64',
@@ -977,14 +978,31 @@ sub main() {
 	    sparc => 'sparc',
 	    sparc64 => 'sparc64',
 	};
-    open my $fh, '-|', 'arch-test', '-n', $nativearch // die "failed to fork(): $!";
+	chomp (my $hostarch = `dpkg --print-architecture`);
+	if ($hostarch ne $nativearch) {
+	    my $pid = open my $fh, '-|' // die "failed to fork(): $!";
+	    if ($pid == 0) {
+		{ exec 'arch-test', '-n', $nativearch; }
+		# if exec didn't work (for example because the arch-test program is
+		# missing) prepare for the worst and assume that the architecture
+		# cannot be executed
+		print "$nativearch: not supported on this machine/kernel\n";
+		exit 1;
+	    }
 	    chomp (my $content = do { local $/; <$fh> });
 	    close $fh;
 	    if ($? != 0 or $content ne "$nativearch: ok") {
+		print STDERR "I: $nativearch cannot be executed, falling back to qemu-user\n";
 		if (!exists $deb2qemu->{$nativearch}) {
 		    die "no mapping from $nativearch to qemu-user binary";
 		}
 		$options->{qemu} = $deb2qemu->{$nativearch};
+	    } else {
+		print STDERR "I: $nativearch can be executed on this $hostarch machine\n";
+	    }
+	} else {
+	    print STDERR "I: chroot architecture $nativearch is equal to the host's architecture\n";
+	}
     }
 
     if (scalar @ARGV > 0) {