Compilation issue : Option -a cannot be used with .cmxa input files

Learning
,
1

I am trying to build a library while my code used to be an executable but now I need to execute my function from another repository.
My intent is to produce a .cmxa file from my main source file ComponentDefinition.ml (so ComponentDefinition.cmxa). This file would be the library for my project.

So my makefile look like this

OCAMLFIND=ocamlfind
OCAMLC=$(OCAMLFIND) ocamlopt
CMO=cmx
CMA=cmxa
INCLUDES=  -package yojson -package opium -package logs -package str -package ounit2 -package lwt_ppx -package cohttp-lwt-unix -package uuidm
OCAMLFLAGS= -thread -linkpkg -g -w -u-s-y $(INCLUDES)

SRC=Value.ml CustomMediaType.ml TypeFormatConstraints.ml TypesFormatsConstraintsManager.ml Parameter.ml Parameters.ml Return.ml Returns.ml Response_.ml InternalReturns.ml TaskDef.ml DbConnector.ml Route.ml RoutePaging.ml FetchUrlRoute.ml RawContentInputRoute.ml RouteManager.ml Task.ml ComponentRouteBuilder.ml ComponentInput.ml ComponentOutput.ml Component.ml ComponentManager.ml SelfDescribe.ml MicroService.ml ComponentDefinition.ml

test: $(SRC:.ml=.$(CMO))
	$(OCAMLC) $(OCAMLFLAGS) -o test $(SRC:.ml=.$(CMO)) Test.ml

app: $(SRC:.ml=.$(CMO)) Main.ml
	$(OCAMLC) $(OCAMLFLAGS) -o app $(SRC:.ml=.$(CMO)) Main.ml

lib: $(SRC:.ml=.$(CMO))
	$(OCAMLC) $(OCAMLFLAGS) -a $(SRC:.ml=.$(CMO)) ComponentDefinition.ml



# Common rules
.SUFFIXES: .ml .mli .$(CMO) .cmi

%.cmi: %.mli
	$(OCAMLC) $(OCAMLFLAGS) -c $<

%.$(CMO): %.ml
	$(OCAMLC) $(OCAMLFLAGS) -c $<

# Clean up
clean:
	rm -f *.cm[ioax]
	rm -f *.o

test and app targets work well, but when I try lib target, I get the error

ocamlfind ocamlopt -thread -linkpkg -g -w -u-s-y -package yojson -package opium -package logs -package str -package ounit2 -package lwt_ppx -package cohttp-lwt-unix -package uuidm -a Value.cmx CustomMediaType.cmx TypeFormatConstraints.cmx TypesFormatsConstraintsManager.cmx Parameter.cmx Parameters.cmx Return.cmx Returns.cmx Response_.cmx InternalReturns.cmx TaskDef.cmx DbConnector.cmx Route.cmx RoutePaging.cmx FetchUrlRoute.cmx RawContentInputRoute.cmx RouteManager.cmx Task.cmx ComponentRouteBuilder.cmx ComponentInput.cmx ComponentOutput.cmx Component.cmx ComponentManager.cmx SelfDescribe.cmx MicroService.cmx ComponentDefinition.cmx ComponentDefinition.ml
Option -a cannot be used with .cmxa input files.

This error is not very documented on the web, how could it be bypassed ?
There is no .cmxa input file in my project (trying to produce one!)

2

The .cmxa files are added by ocamlfind’s -linkpkg flag. You should only use that when you actually need the libraries, i.e. when making an executable.

3

Thank you, it solved my case! I know better the ocamlfind -linkpkg flag now.