[MacPorts] #23320: fail to install wxWidgets-devel +universal on snow leopard

[MacPorts]

#23320: fail to install wxWidgets-devel +universal on snow leopard
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 Reporter:  klebermagno@…          |       Owner:  jwa@…           
     Type:  defect                 |      Status:  new             
 Priority:  Normal                 |   Milestone:                  
Component:  ports                  |     Version:  1.8.2           
 Keywords:                         |        Port:  wxWidgets-devel 
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Comment(by cdavis@…):

 All right, I've worked through this, and there are three distinct issues
 here:

 1. Using dependency options and compiling PCH files

 You can't do either of those with multiple arch flags. Even if you remove
 the dependency options, when gcc tries to precompile a header into a PCH
 given multiple arch flags, it will instead try to compile a regular ol'
 program instead. (ld will complain that '_main' is undefined.)

 I fixed it locally by the port belong to the muniversal group.

 2. OBJCXXFLAGS isn't set

 OK, you got past the first problem, and wxWidgets is building just fine.
 Suddenly, the build stops with an error message. Looking at the log file
 reveals a bunch of 'file is not of the architecture being linked' messages
 from ld.

 Inspecting the files that were compiled wrong reveals something telling:
 They're all Objective-C++ files! For some reason, wx's build system uses
 the OBJCXXFLAGS variable instead of the CXXFLAGS variable when compiling
 an Objective-C++ file. Since the Portfile didn't set OBJCXXFLAGS, no
 Objective-C++ sources get built for the right architecture. I fixed it by
 manually playing with the top-level makefile, but the right way to fix
 this is to set OBJCXXFLAGS in the Portfile during the configure stage.

 3. Symlink merging madness

 Finally, you solved problems 1 and 2 and got the build to finish. Because
 we put wxWidgets-devel in the muniversal group, now MacPorts will install
 the two build trees into two destroots, then merge them together.
 Unfortunately, there's one small problem with that: MacPorts doesn't know
 how to merge symlink files. Here's a relevant snippet from the log:

 {{{
 :debug:destroot universal: merge: /opt/local/lib/wx-devel/bin/wx-config
 only exists in
 /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports
 .org_release_ports_graphics_wxWidgets-devel/work/destroot-x86_64
 :debug:destroot universal: merge: /opt/local/lib/wx-devel/bin/wx-config
 only exists in
 /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports
 .org_release_ports_graphics_wxWidgets-devel/work/destroot-i386
 }}}

 So it knows that both symlinks are there, but it thinks they're distinct.
 So, it copies each one over to the merged destroot. Unfortunately, copying
 the second one fails because the file already exists:

 {{{
 :error:destroot Target org.macports.destroot returned: error copying
 "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports
 .org_release_ports_graphics_wxWidgets-
 devel/work/destroot-i386//opt/local/lib/wx-devel/bin/wx-config" to
 "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports
 .org_release_ports_graphics_wxWidgets-devel/work/destroot-
 intel//opt/local/lib/wx-devel/bin/wx-config": file already exists
 }}}

 This is as far as I got. One possible solution is to forcibly copy the
 symlink over. However, I think the real solution is to teach MacPorts to
 recognize and handle symlinks properly when merging two destroots.

-- 
Ticket URL: <https://trac.macports.org/ticket/23320#comment:9>
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