A quick patch to silence a monotone warning I started seeing:

diff --git a/IkiWiki/Plugin/monotone.pm b/IkiWiki/Plugin/monotone.pm
index 4b9be31..9d4e280 100644
--- a/IkiWiki/Plugin/monotone.pm
+++ b/IkiWiki/Plugin/monotone.pm
@@ -55,7 +55,7 @@ sub checkconfig () {
        error("Monotone version too old, is $version but required 0.38");
    }

-   if (length $config{mtn_wrapper}) {
+   if (defined $config{mtn_wrapper} && length $config{mtn_wrapper}) {
        push @{$config{wrappers}}, {
            wrapper => $config{mtn_wrapper},
            wrappermode => (defined $config{mtn_wrappermode} ? $config{mtn_wrappermode} : "06755"),

Thanks, done