[MacPorts] #50725: compilers-1.0 portgroup allows selection of nonexistent variant to defeat default variant

[MacPorts]

#50725: compilers-1.0 portgroup allows selection of nonexistent variant to defeat
default variant
--------------------------+--------------------
 Reporter:  ryandesign@…  |      Owner:  sean@…
     Type:  defect        |     Status:  new
 Priority:  Normal        |  Milestone:
Component:  ports         |    Version:  2.3.99
 Keywords:                |       Port:
--------------------------+--------------------
 As an example, the py27-scipy port has compiler variants, and the gfortran
 variant should be used if the user has not already selected another:

 {{{
 $ port info py27-scipy
 py27-scipy @0.17.0 (python)
 Variants:             atlas, clang37, gcc48, gcc49, gcc5, gcc6,
 [+]gfortran, llvm, openblas

 Description:          An opensource library of scientific tools for Python
 Homepage:             http://www.scipy.org/

 Build Dependencies:   gcc5
 Library Dependencies: python27, py27-numpy, py27-nose, swig-python, libgcc
 Platforms:            darwin
 License:              BSD
 Maintainers:          sean at macports.org, michaelld at macports.org,
 openmaintainer
 }}}

 The port does not have a gcc44 variant, but if I select it, this
 erroneously causes the port to no longer use gfortran as the default:

 {{{
 $ port info py27-scipy +gcc44
 py27-scipy @0.17.0 (python)
 Variants:             atlas, clang37, gcc48, gcc49, gcc5, gcc6, gfortran,
 llvm, openblas

 Description:          An opensource library of scientific tools for Python
 Homepage:             http://www.scipy.org/

 Library Dependencies: python27, py27-numpy, py27-nose, swig-python
 Platforms:            darwin
 License:              BSD
 Maintainers:          sean at macports.org, michaelld at macports.org,
 openmaintainer
 }}}

 If I try to install this way, I'll get an error:

 {{{
 $ sudo port install py27-scipy +gcc44
 --->  Computing dependencies for py27-scipy
 --->  Fetching distfiles for py27-scipy
 Error: Failed to fetch py27-scipy: must set at least one Fortran variant
 Error: See /opt/local/var/macports/logs
 /_Users_rschmidt_macports_dports_python_py-scipy/py27-scipy/main.log for
 details.
 Error: Follow http://guide.macports.org/#project.tickets to report a bug.
 Error: Processing of port py27-scipy failed
 }}}

 The compilers portgroup should ignore selected variants the port does not
 offer.

-- 
Ticket URL: <https://trac.macports.org/ticket/50725>
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