`make install` not copying ocamlnat in OCaml 4.14.2

Ecosystem
1

Hi all,

This could be a question that had been already answered by somebody in the past, but I found that in OCaml 4.14.2 make install does not copy ocamlnat even if it was built by make world.opt.

I was downloading & building this source code: https://github.com/ocaml/ocaml/archive/4.14.2.tar.gz

Is there a background why make install of OCaml 4.14.2 was designed to not copy the file into its installation directory?

2

The ocamlnat REPL is an experimental tool that is not part of the standard installation of the compiler.

3

Thanks for a quick reply! :slight_smile:

Actually I must have discovered earlier that configuration has --enable-native-toplevel which indeed installs the file. Including this in my reply to record for someone who might be interested in its availability as well…

4

I am wondering whether my ocamlnat was built with right configuration options or it had missing ones. Running #use "topfind" is raising an undefined symbol error and one additional warning:

$ ocamlnat
OCaml version 4.14.2 - native toplevel
Enter #help;; for help.

# #use "topfind";;
>> Fatal error: Toploop.dll_run /tmp/camlTOP223e2fe.so: undefined symbol: camlTopfind
File "_none_", line 1:
Warning 58 [no-cmx-file]: no cmx file was found in path for module TOP1, and its interface was not compiled with -opaque
- : unit = ()
Findlib has been successfully loaded. Additional directives:
  #require "package";;      to load a package
  #list;;                   to list the available packages
  #camlp4o;;                to load camlp4 (standard syntax)
  #camlp4r;;                to load camlp4 (revised syntax)
  #predicates "p,q,...";;   to set these predicates
  Topfind.reset();;         to force that packages will be reloaded
  #thread;;                 to enable threads

- : unit = ()
#

I used ./configure --enable-native-toplevel when building OCaml 4.14.

5

IIRC it’s not possible to use ocamlfind with ocamlnat. Omod should work but apparently there were changes that I didn’t see fly by (ocamlnat is not checked by opam-ci on new releases).

6

With the new toploop API unification do you know if there is a way to detect whether I’m running in the bytecode or native code toplevel ?

It seems I could almost get rid of #use {omod,down}.top vs #use {omod,down}.nattop and thus have a single .ocamlinit that works with both toplevels but I need this information bit.

EDIT: Oh I forgot that Sys.backend_type is a thing nowadays.

8

In fact it seems that’s no longer true, I guess thanks to the ocamlnat/ocaml API unification done by @AltGr upstream (thanks!).

I had a closer look at the error you reported it is triggered by the test here. This doesn’t prevent topfind from loading on 4.14.2 but it does on 5.2.0~rc1. However even on 4.14.2 it seems to fail to load libraries correctly I have opened an issue.

I’m glad to report that this is fixed. And with:

> cat ~/.config/ocaml/init.ml 
#use "down.top"
#use "omod.top"

you can now simply invoke ocaml or ocamlnat regardless (also tested with 5.2.0~rc1).

> ocaml
OCaml version 4.14.2
Enter #help;; for help.

Down v0.3.0-7-ge3a4f38 loaded. Type Down.help () for more info.
Omod v0.0.4-3-gb0d2684 loaded. Type Omod.help () for more info.
# ^D
> ocamlnat
OCaml version 4.14.2 - native toplevel
Enter #help;; for help.

Down v0.3.0-7-ge3a4f38 loaded. Type Down.help () for more info.
Omod v0.0.4-3-gb0d2684 loaded. Type Omod.help () for more info.
# ^D

For those interested I also updated ocaml-repo-ocamlnat with 4.14.2 and 5.2.0~rc1. I will make new omod and down releases soon.

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