[opam-devel] Finding dependencies of a specific OPAM package

[Anil Madhavapeddy]

Good point -- I'm looking for all the reverse dependency package cone of
Cohttp that are installable for a particular version of Cohttp.  I will
then install each of them separately, so there's no requirement for the
results to all be coinstallable.

The goal is to check that a new version of Cohttp doesn't break an existing
package that worked with an earlier version, so that we can add an upper
bound to the opam package before merging the new release (and of course to
use this more generally with other packages too).

-anil

> On 23 Mar 2015, at 16:43, Roberto Di Cosmo <roberto at dicosmo.org> wrote:
> 
> Computing the reverse dependency cone of a package P is just a matter of
> visiting the dependency graph, and you do not need any call to the solver
> for this. 
> 
> But this reverse dependency cone may very well contain packages not coinstallable with P.
> 
> For example, if you have
> 
> package: a
> depends: cohttp, b
> 
> package: cohttp
> version: 1
> conflicts: b
> 
> package: cohttp
> version: 2
> 
> Then a is a reverse dependency for both versions of cohttp, even if it is
> coinstallable only with version 2.
> 
> If you want all packages in the reverse dependency cone of cohttp _that are also
> coinstallable with it_, then you need to actually call the solver on each of
> them.
> 
> --
> Roberto
> 
> On Mon, Mar 23, 2015 at 04:27:47PM +0000, Anil Madhavapeddy wrote:
>> I'm trying to find all the reverse dependency of a particular version of Cohttp.  I can do:
>> 
>>    opam list --depends-on cohttp --rec
>> 
>> to get all of the dependencies for all versions.  Unfortunately trying:
>> 
>>    opam list --depends-on cohttp.0.15.2 --rec
>> 
>> gives the same results (including packages that depend on earlier versions of Cohttp and are specifically not installable with cohttp.0.15.2)
>> 
>> Any suggestions on how to resolve this?  I guess going through the list individually to check constraints is one way, but feely very clunky (and slow due to going through the solver so many times).
>> 
>> -anil
>> _______________________________________________
>> opam-devel mailing list
>> opam-devel at lists.ocaml.org
>> http://lists.ocaml.org/listinfo/opam-devel
> 
> -- 
> Roberto Di Cosmo
> 
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