[MacPorts] #52479: gpgme: install headers in a private location to avoid conflict and/or header confusion

[MacPorts]

#52479: gpgme: install headers in a private location to avoid conflict and/or
header confusion
-------------------------+--------------------------------
 Reporter:  rjvbertin@…  |      Owner:  macports-tickets@…
     Type:  defect       |     Status:  new
 Priority:  High         |  Milestone:
Component:  ports        |    Version:  2.3.4
 Keywords:  haspatch     |       Port:  gpgme
-------------------------+--------------------------------
 port:gpgme was recently updated to 1.7.0 and to build the C++ wrappers
 (but only when using libc++, for some reason).

 Several issues result from this:

 - port:kdepimlibs4 installs its own gpgme++ libraries and headers;
 unmodified those go into ${prefix}/include/gpgme++ and thus clash with the
 ones from port:gpgme

 - KDE actually maintains its own C++ wrappers (fork or original I don't
 know). It seems that (very recent) KF5 code can co-exist with the headers
 from port:gpgme, but the KDE4 code that uses these C++ wrappers is now old
 and mostly unmaintained. It is unlikely that it will build and run against
 the 1.7.0 gpgme++ wrappers without significant modification of the build
 system and code (see https://trac.macports.org/ticket/52342 and
 https://trac.macports.org/ticket/52470). The 1.7.0 gpgme C libraries are
 fine, though.

 The library binaries from port:kdepimlibs4 and port:gpgpme do not clash,
 so the main issue at hand is to avoid headerfile confusion where a gpgme++
 header is included from port:gpgme when one from port:kdepimlibs4 is
 required, or vice versa.

 It is trivial to reconfigure port:kdelibs4 such that headers from KDE4
 ports are installed into, say, ${prefix}/include/KDE4. This has been
 proposed already as it is required for concurrent installation of KDE4 and
 KF5 ports.

 It is relatively trivial to do something similar with port:gpgme, and the
 attached patch contains an implementation.
 I tested this approach and can confirm that
 - The KDEPIM4 ports as well as port:kde4-runtime build and run provided
 the KDE4 headers are installed as described above
 - kf5-gpgmepp and kf5-kwallet also build (with an upstream patch to
 support gpgme 1.7). I have not yet made ports for other KF5 software that
 uses gpgme.

 As far as I know, installing the C++ headers is a new feature in
 port:gpgme 1.7 and as such I *presume* that only few ports depend on it as
 yet. Either way, the proposed change should be completely transparent and
 doesn't change anything link dependencies. No rev-bumping of dependents is
 required. However, it might be useful to add a variant to control building
 (or omission) of the C++ wrappers.

 See also https://bugs.gnupg.org/gnupg/issue2733

-- 
Ticket URL: <https://trac.macports.org/ticket/52479>
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