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+@title Rebuilding the Library Map
+@group working
+
+When you add or move classes or modules, you need to rebuild the Phutil library
+map.
+
+= Overview =
+
+Phutil libraries include a list of every symbol (class and function) defined
+in them, and some other information like dependencies between symbols. This
+map is generated by running the script:
+
+  arcanist/scripts/phutil_mapper.php <library_root>
+  
+For instance, to regenerate the libphutil map itself, you'd run:
+
+  libphutil/ $ ../arcanist/scripts/phutil_mapper.php src/
+  
+When you add new modules, remove modules, or move symbols around in existing
+modules, you need to regenerate the map.