Use nowide from Boost. From Fedora.

Index: tests/CMakeLists.txt
--- tests/CMakeLists.txt.orig
+++ tests/CMakeLists.txt
@@ -1,8 +1,8 @@
-set(BOOST_REQUIRED_COMPONENTS system date_time chrono log log_setup thread filesystem regex)
+set(BOOST_REQUIRED_COMPONENTS system date_time chrono log log_setup thread filesystem regex nowide)
 if (LEATHERMAN_USE_LOCALES)
     set(BOOST_REQUIRED_COMPONENTS ${BOOST_REQUIRED_COMPONENTS} locale)
 endif()
-find_package(Boost "1.54" REQUIRED COMPONENTS ${BOOST_REQUIRED_COMPONENTS})
+find_package(Boost "1.73" REQUIRED COMPONENTS ${BOOST_REQUIRED_COMPONENTS})
 
 include_directories(BEFORE ${LEATHERMAN_CATCH_INCLUDE} ${LEATHERMAN_INCLUDE_DIRS})
 add_executable(leatherman_test main.cc ${LEATHERMAN_TEST_SRCS})
