This error about a single package could get it ignored on older opam versions, but I don't think it should ever make the full update command fail. In other words, this should be harmless unless you want to install `pxp`. What were the end of output and return code from opam ?

I'll report the error for ocamlfind+ocp1 ; you can work around it by pinning to a different version, e.g. `opam pin add ocamlfind 1.5.5`.

On the `ocamlfind-ocj` and `ocj-ocamlfind`, that should probably be cleaned up in the opam repository.

Best,
Louis Gesbert -- OCamlPro

> - Kenneth Adam Miller, 18/07/2015 16:01 -
> Thanks for your reply!
> 
> Yeah that's possible; I was trying to update and that was giving me an
> error as well.
> 
> opam update
> ...
> [ERROR] At ~/.opam/repo/default/packages/pxp/pxp.1.2.7/opam:4:52:
>   Not a recognised version-control URL
> 
> I don't know what that's about either. Do you think possibly I  just need
> to get update to succeed in order that dependency computation move forward
> correctly? I'd like to at least rule out not repeating anything or dealing
> with version issues with I could be on the edge.
> 
> On Sat, Jul 18, 2015 at 3:44 PM, Gabriel Scherer <gabriel.scherer@gmail.com>
> wrote:
> 
> > This looks like a problem with the dependency computation algorithm.
> > If you have not installed an external CUDF solver such as aspcud
> > (which does a better job than the internal solver of OPAM), it may
> > solve such spurious dependency issues.
> >   https://opam.ocaml.org/doc/Specifying_Solver_Preferences.html
> >
> > (Or use the remove server farm
> > http://cudf-solvers.irill.org/index.html if you don't want to install
> > an external solver and don't mind your install requests to be sent
> > over the network)
> >
> > On Sat, Jul 18, 2015 at 9:36 PM, Kenneth Adam Miller
> > <kennethadammiller@gmail.com> wrote:
> > > There are duplicate ocamlfind specific opam packages:
> > >
> > > opam search ocamlfind
> > > ...
> > > ocamlfind-ocj             --  A library manager for OCaml
> > > ocj-ocamlfind             --  A library manager for OCaml
> > >
> > >
> > >
> > > In a second note, I have to install the library base-bytes. ocamlfind
> > > 1.5.5-ocp is required by base-bytes, when a non-ocp install of ocamlfind
> > was
> > > working fine. ocamlfind 1.5.5-ocp blows up with the following errors:
> > >
> > > #=== ERROR while installing ocamlfind.1.5.5+ocp1
> > > ==============================#
> > > # opam-version 1.2.0
> > > # os           linux
> > > # command      make all
> > > # path
> > >
> > /home/kennethadammiller/.opam/ocamljava-2.0-alpha3/build/ocamlfind.1.5.5+ocp1
> > > # compiler     ocamljava-2.0-alpha3
> > > # exit-code    2
> > > # env-file
> > >
> > /home/kennethadammiller/.opam/ocamljava-2.0-alpha3/build/ocamlfind.1.5.5+ocp1/ocamlfind-12342-e7966f.env
> > > # stdout-file
> > >
> > /home/kennethadammiller/.opam/ocamljava-2.0-alpha3/build/ocamlfind.1.5.5+ocp1/ocamlfind-12342-e7966f.out
> > > # stderr-file
> > >
> > /home/kennethadammiller/.opam/ocamljava-2.0-alpha3/build/ocamlfind.1.5.5+ocp1/ocamlfind-12342-e7966f.err
> > > ### stdout ###
> > > # ...[truncated]
> > > #           ocaml_args.cmo frontend.cmo
> > > # if [ "false" = "true" ]; then                 \
> > > # cp topfind.ml.in topfind.ml;                             \
> > > # else                                                             \
> > > # sed -e '/PPXOPT_BEGIN/,/PPXOPT_END/ d' topfind.ml.in     \
> > > # > topfind.ml ;                                   \
> > > # fi
> > > # ocamlc -I +compiler-libs -c topfind.mli
> > > # ocamlc -I +compiler-libs -g -c topfind.ml
> > > # make[1]: Leaving directory
> > >
> > `/home/kennethadammiller/.opam/ocamljava-2.0-alpha3/build/ocamlfind.1.5.5+ocp1/src/findlib'
> > > ### stderr ###
> > > # File "itest-aux/ppx.ml", line 1, characters 0-25:
> > > # Error: Unbound value Toploop.preprocess_phrase
> > > # Makefile:160: depend: No such file or directory
> > > # File "topfind.ml", line 1:
> > > # Error: The files
> > >
> > /home/kennethadammiller/.opam/ocamljava-2.0-alpha3/lib/ocaml/compiler-libs/toploop.cmi
> > > #        and
> > >
> > /home/kennethadammiller/.opam/ocamljava-2.0-alpha3/lib/ocaml/compiler-libs/parsetree.cmi
> > > #        make inconsistent assumptions over interface Warnings
> > > # make[1]: *** [topfind.cmo] Error 2
> > > # make: *** [all] Error 2
> > >
> > >
> > > =-=- Error report
> > > -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
> > > The following failed
> > >  - install   ocamlfind.1.5.5+ocp1
> > > Due to the errors, the following have been cancelled
> > >  - install   base-bytes.base
> >
> 
>