[Caml-list] Opam problem: cannot upgrade yojson

[Alan Schmitt <alan.schmitt@polytechnique.org>]

Hello,

I cannot seem to upgrade yojson using opam, because I'm stuck with a
version I cannot remove:

,----
| $ opam info yojson
|              package: yojson
|              version: 1.1.3
|              depends: ocamlfind & cppo & easy-format & biniou <= 1.0.3
|    installed-version: yojson.1.1.3 [4.00.1]
|   available-versions: 1.0.3, 1.1.6
|          description: Yojson is an optimized parsing and printing library for the JSON format 
| 
| It addresses a few shortcomings of json-wheel including 2x speedup,
| polymorphic variants and optional syntax for tuples and variants.
| 
| ydump is a pretty-printing command-line program provided with the
| yojson package.
| 
| The program atdgen can be used to derive OCaml-JSON serializers and
| deserializers from type definitions.
| 
| $ opam remove yojson
| 
| $ opam info yojson
|              package: yojson
|              version: 1.1.3
|              depends: ocamlfind & cppo & easy-format & biniou <= 1.0.3
|    installed-version: yojson.1.1.3 [4.00.1]
| ...
| 
| $ opam upgrade
| The following actions will be performed:
|  - install yojson.1.1.6
| 1 to install | 0 to reinstall | 0 to upgrade | 0 to downgrade | 0 to remove
| 
| =-=-= Installing yojson.1.1.6 =-=-=
| The archive for yojson.1.1.6 is in the local cache.
| Extracting /Users/schmitta/.opam/archives/yojson.1.1.6+opam.tar.gz.
| Building yojson.1.1.6:
|   make
|   make install
| The compilation of yojson.1.1.6 failed.
| Uninstalling yojson.1.1.6:
|   ocamlfind remove yojson
| 
| 
| ==== ERROR [while installing yojson.1.1.6] ====
| # opam-version    1.0.0
| # os              darwin
| # command         make install
| # path            /Users/schmitta/.opam/4.00.1/build/yojson.1.1.6
| # exit-code       2
| # env-file        /Users/schmitta/.opam/4.00.1/build/yojson.1.1.6/yojson-ffb3fd.env
| # stdout-file     /Users/schmitta/.opam/4.00.1/build/yojson.1.1.6/yojson-ffb3fd.out
| # stderr-file     /Users/schmitta/.opam/4.00.1/build/yojson.1.1.6/yojson-ffb3fd.err
| ### stdout ###
| test ! -f ydump || cp ydump /Users/schmitta/.opam/4.00.1/bin/
| test ! -f ydump.exe || cp ydump.exe /Users/schmitta/.opam/4.00.1/bin/
| ocamlfind install yojson META \
|           $(ls yojson.mli yojson_biniou.mli yojson.cmi yojson_biniou.cmi yojson.cmo yojson_biniou.cmo yojson.cmx yojson_biniou.cmx yojson.o yojson_biniou.o)
| ### stderr ###
| ocamlfind: Package yojson is already installed
|  - (file /Users/schmitta/.opam/4.00.1/lib/yojson/META already exists)
| make: *** [install] Error 2
| 
| 'opam upgrade' failed.
`----

Am I doing something wrong here, or is this a bug?

Thanks,

Alan