Use nowide from Boost. From Fedora.

Index: file_util/CMakeLists.txt
--- file_util/CMakeLists.txt.orig
+++ file_util/CMakeLists.txt
@@ -1,9 +1,8 @@
-find_package(Boost 1.54 REQUIRED COMPONENTS regex filesystem system)
+find_package(Boost 1.73 REQUIRED COMPONENTS regex filesystem system nowide)
 
 add_leatherman_deps("${Boost_LIBRARIES}")
 add_leatherman_includes("${Boost_INCLUDE_DIRS}")
 
-leatherman_dependency(nowide)
 leatherman_dependency(locale)
 leatherman_dependency(logging)
 leatherman_dependency(util)
