Many broken things since recent upgrade (ocamlrun, sexplib, camlp4)

[p4bl0-]

Hello,

First, sorry for that issue title, but I don't know how to give a specific name to all the issues I'm having right now.

Here is what happened:

I updated my Debian, which installed the a new version of Opam. Hoping it would fix all the problems I had (see issue #1671), I moved my ~/.opam to somewhere else and restarted from scratch.
I ran opam init, then opam switch 4.02.1, then opam install batteries menhir merlin sexplib utop which are the vital minimum for me. Everything went fine until the very end of the installation, which is already an improvement.

However, I can't start utop as it immediatly fails with this message:

*** Error in `/home/p4bl0/.opam/4.02.1/bin/ocamlrun': double free or corruption (out): 0x000000000238a640 ***

I also can't compile my code which worked before as ocamlbuild segfaults while running external preprocessor on a file which depends on sexplib:

+ ocamlfind ocamldep -syntax camlp4o -package batteries -package sexplib.syntax -modules computation.ml > computation.ml.depends
Segmentation fault
File "computation.ml", line 1:
Error: Error while running external preprocessor
Command line: camlp4 '-I' '/home/p4bl0/.opam/4.02.1/lib/ocaml/camlp4' '-I' '/home/p4bl0/.opam/4.02.1/lib/type_conv' '-I' '/home/p4bl0/.opam/4.02.1/lib/ocaml' '-I' '/home/p4bl0/.opam/4.02.1/lib/ocaml' '-I' '/home/p4bl0/.opam/4.02.1/lib/sexplib' '-I' '/home/p4bl0/.opam/4.02.1/lib/sexplib' '-parser' 'o' '-parser' 'op' '-printer' 'p' 'pa_type_conv.cma' 'unix.cma' 'bigarray.cma' 'sexplib.cma' 'pa_sexp_conv.cma'  'computation.ml' > /tmp/ocamlpp26cacc

And indeed, if I start the toplevel and enter #require "sexplib.syntax", it segfaults.

I don't really know where to submit these bug: sexplib? ocamlbuild? here? My guess was that here at least people could send the issue upstream if necessary.

Also, I know it's very personnal but I may not be the only one in this situation: I'm attending the The Joint EasyCrypt-F*-CryptoVerif School 2014 next week and I really need my OCaml installation to be working by then as I will need it to install and run the required software.

[p4bl0-]

FWIW, everything seems to be fine with Opam 1.2 and OCaml 4.01.0 :).

[AltGr]

Glad to hear it. It seems that your installation mixed stuff from different versions of OCaml (probably within and outside OPAM); I would check the PATH variable, and check where the different tools come from: which ocaml, which utop, which camlp4o, which ocamlrun, which ocamlfind etc.

Make sure you've run eval $(opam config env) too, or that your startup scripts have been properly updated (depending on your shell, opam may not have found the right file or place to add its hook. See #533)

[p4bl0-]

Thanks for your answer :).
I don't think the problem is mixed stuff. I already checked before posting here that the PATH was right and it was. Here is the output of the which commands you list for instance:

[p4bl0@carotte:~] - 10:44:36 
λ which ocaml
/home/p4bl0/.opam/4.02.1/bin/ocaml
[p4bl0@carotte:~] - 10:44:46 
λ which utop
/home/p4bl0/.opam/4.02.1/bin/utop
[p4bl0@carotte:~] - 10:44:49 
λ which camlp4o
/home/p4bl0/.opam/4.02.1/bin/camlp4o
[p4bl0@carotte:~] - 10:44:54 
λ which ocamlrun
/home/p4bl0/.opam/4.02.1/bin/ocamlrun
[p4bl0@carotte:~] - 10:45:01 
λ which ocamlfind
/home/p4bl0/.opam/4.02.1/bin/ocamlfind

[AltGr]

Closing as I couldn't reproduce and this seems an isolated issue. Stuff regarding environment variables setup and switching has been fixed since 1.2 so that may be it.
Feel free to reopen, of course, if anything similar happens again.