[MacPorts] #57943: boost pulled in from gexiv2 fails for python target

[MacPorts]

#57943: boost pulled in from gexiv2 fails for python target
-----------------------+--------------------
  Reporter:  rmottola  |      Owner:  (none)
      Type:  defect    |     Status:  new
  Priority:  Normal    |  Milestone:
 Component:  ports     |    Version:
Resolution:            |   Keywords:
      Port:  boost     |
-----------------------+--------------------
Changes (by ryandesign):

 * keywords:  Lion python python27 python37 variant conflict =>


Old description:

> upgrade wants to pull in gexiv2:
>
> The following ports will be rebuilt:
>  gexiv2 @0.10.8+python27+python36
>  gimp2 @2.10.6+python27+quartz
>
> gexiv2 pulls in boost, a port which I do not have yet installed, however
> it fails:
>
> Error: boost: Variant python27 conflicts with python36
> Error: Unable to open port: Error evaluating variants
> Error: rev-upgrade failed: Error rebuilding gexiv2

New description:

 upgrade wants to pull in gexiv2:

 {{{
 The following ports will be rebuilt:
  gexiv2 @0.10.8+python27+python36
  gimp2 @2.10.6+python27+quartz
 }}}

 gexiv2 pulls in boost, a port which I do not have yet installed, however
 it fails:

 {{{
 Error: boost: Variant python27 conflicts with python36
 Error: Unable to open port: Error evaluating variants
 Error: rev-upgrade failed: Error rebuilding gexiv2
 }}}

--

Comment:

 The gexiv2 port intentionally allows one python2x and one python3x variant
 to be selected. However the boost port intentionally allows only one
 python variant to be selected regardless of version.

 MacPorts passes variant selections (apparently regardless of how the
 variant selection was supplied—by you on the command line, or in your
 variants.conf, or by a port in its default_variants) down to any
 dependencies that are not yet installed.

 Clean boost and install it with either the python27 or python36 variant.

-- 
Ticket URL: <https://trac.macports.org/ticket/57943#comment:1>
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