[opam-devel] shared directory

[Louis Gesbert]

Le mercredi 20 novembre 2013 19:59:28 Sean McLaughlin a écrit :
> I'm installing elisp files.  What would you tell the user to put in their
> .emacs?
> This is Louis' proposal:
> 
> (setq path-to-opam-shared
>   (replace-regexp-in-string "\n" "" (shell-command-to-string "opam config
> var share")))
> 
> It would be nicer to do
> 
> (setq path-to-opam-shared "~/.opam/current/shared")
> 

I agree the symlink looks cleaner, and is probably slightly more efficient. There might be another difference between the two if you use `opam switch` after you started emacs though.

To sum up, there is no problem with adding the symlink for convenience, but we're afraid it may cause issues if used unknowingly. So the question is really "is it worth that risk ?"
I can add it if the answer is yes.


> What is opam exec?
> 
> $ opam --version
> 1.1.0
> $ opam exec
> opam: unknown command `exec'
> Usage: opam COMMAND ...
> Try `opam --help' for more information.
> EXIT STATUS 1
> 
> 
> 
> 
> On Wed, Nov 20, 2013 at 7:17 PM, Anil Madhavapeddy <anil at recoil.org> wrote:
> 
> > It breaks the nice property that you can start a shell with "opam exec"
> > and have it do the right thing with respect to dependent tools.  If your
> > scripts depend on an environment variable, then they'll work, but a symlink
> > approach isn't quite as flexible.
> >
> > Having said that, if people think that the symlink is really convenient
> > and don't care about `opam exec`, I have no objection to a symlink being
> > maintained.
> >
> > -anil
> >
> > On 20 Nov 2013, at 13:53, Louis Gesbert <louis.gesbert at ocamlpro.com>
> > wrote:
> >
> > Updating a symlink whenever you do `opam switch` wouldn't be too much of a
> > problem indeed. What I am concerned about is that people may start using it
> > from opam, which would break when the OPAMROOT and --root opam options are
> > used.
> >
> >
> > But perhaps I am being too cautious ? I'm myself using a ~/opam link
> > pointing to ~/.opam/4.01.0 ...
> >
> >
> > Best,
> > Louis
> >
> >
> > Le lundi 18 novembre 2013 10:17:56 Sean McLaughlin a écrit :
> > > Hi Louis,
> > >
> > > What are the issues to using a symlink? Couldn't opam switch just move it
> > > around?
> > >
> > > Best,
> > >
> > > Sean
> > >
> > >
> > > On Mon, Nov 18, 2013 at 3:30 AM, Louis Gesbert
> > > <louis.gesbert at ocamlpro.com>wrote:
> > >
> > > > Le dimanche 17 novembre 2013 16:54:15 Sean McLaughlin a écrit :
> > > >
> > > > > I'm trying to package a library that installs files in share. When I
> > had
> > > >
> > > > > only one compiler installed, the %{prefix}% argument sent them to
> > > >
> > > > > .opam/system/share. However, when I installed another compiler and
> > made
> > > > it
> > > >
> > > > > current, the files went into .opam/4.00.1/share. I am trying to tell
> > the
> > > >
> > > > > user where to find the files. Is there a generic directory where I
> > could
> > > >
> > > > > point the user? Perhaps you could make a symlink 'current' for the
> > > >
> > > > > current compiler?
> > > >
> > > >
> > > >
> > > > You should use $(opam config var prefix)/share, or even $(opam config
> > var
> > > > share). A symlink could be an option worth considering, but it has its
> > own
> > > > issues.
> > > >
> > > >
> > > >
> > > > Best,
> > > >
> > > > Louis
> > > >
> > _______________________________________________
> > opam-devel mailing list
> > opam-devel at lists.ocaml.org
> > http://lists.ocaml.org/listinfo/opam-devel
> >
> >
> >
> > _______________________________________________
> > opam-devel mailing list
> > opam-devel at lists.ocaml.org
> > http://lists.ocaml.org/listinfo/opam-devel
> >
> >
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