Index: head/devel/kyua/files/patch-utils_datetime.cpp
===================================================================
--- head/devel/kyua/files/patch-utils_datetime.cpp	(revision 439016)
+++ head/devel/kyua/files/patch-utils_datetime.cpp	(revision 439017)
@@ -1,23 +1,20 @@
-
-$FreeBSD$
-
 --- utils/datetime.cpp.orig
 +++ utils/datetime.cpp
 @@ -590,11 +590,12 @@
  datetime::delta
  datetime::timestamp::operator-(const datetime::timestamp& other) const
  {
 -    if ((*this) < other) {
 -        throw std::runtime_error(
 -            F("Cannot subtract %s from %s as it would result in a negative "
 -              "datetime::delta, which are not supported") % other % (*this));
 -    }
 +    /*
 +     * XXX-BD: gettimeofday isn't necessicarily monotonic so return the
 +     * smallest non-zero delta if time went backwards.
 +     */
 +    if ((*this) < other)
 +        return datetime::delta::from_microseconds(1);
      return datetime::delta::from_microseconds(to_microseconds() -
                                                other.to_microseconds());
  }