Make dune build verbose

Index: ocamldeps/ppx_derivers/Makefile
--- ocamldeps/ppx_derivers/Makefile.orig
+++ ocamldeps/ppx_derivers/Makefile
@@ -2,7 +2,7 @@ INSTALL_ARGS := $(if $(PREFIX),--prefix $(PREFIX),)
 
 .PHONY: all
 all:
-	dune build
+	dune build --verbose
 
 .PHONY: install
 install:
