gtk3 on Snow Leopard build failed

[Joshua Root]

> ...and things had gone so nicely on Snow Leopard for awhile now, until this:
>
> :notice:build --->  Building gtk3
> :debug:build Executing org.macports.build (gtk3)
> :info:build --->  Building gtk3 for architecture x86_64
> :debug:build setting option build.dir to /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_gnome_gtk3/gtk3/work/build-x86_64
> :debug:build Environment:
> :debug:build CC_PRINT_OPTIONS='YES'
> :debug:build CC_PRINT_OPTIONS_FILE='/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_gnome_gtk3/gtk3/work/.CC_PRINT_OPTIONS'
> :debug:build CPATH='/opt/local/include'
> :debug:build CPLUS_INCLUDE_PATH='/opt/local/include/LegacySupport'
> :debug:build C_INCLUDE_PATH='/opt/local/include/LegacySupport'
> :debug:build DEVELOPER_DIR='/Developer'
> :debug:build LIBRARY_PATH='/opt/local/lib'
> :debug:build MACOSX_DEPLOYMENT_TARGET='10.6'
> :debug:build MACPORTS_LEGACY_SUPPORT_CPPFLAGS='-isystem/opt/local/include/LegacySupport'
> :debug:build MACPORTS_LEGACY_SUPPORT_ENABLED='1'
> :debug:build MACPORTS_LEGACY_SUPPORT_LDFLAGS='-L/opt/local/lib -lMacportsLegacySupport'
> :debug:build OBJCPLUS_INCLUDE_PATH='/opt/local/include/LegacySupport'
> :debug:build OBJC_INCLUDE_PATH='/opt/local/include/LegacySupport'
> :info:build Executing:  cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_gnome_gtk3/gtk3/work/build-x86_64" && /opt/local/bin/ninja -j4 CC='/opt/local/bin/clang-mp-8.0 -arch x86_64' CC_FOR_BUILD='/opt/local/bin/clang-mp-8.0 -arch x86_64' -v
> :debug:build system:  cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_gnome_gtk3/gtk3/work/build-x86_64" && /opt/local/bin/ninja -j4 CC='/opt/local/bin/clang-mp-8.0 -arch x86_64' CC_FOR_BUILD='/opt/local/bin/clang-mp-8.0 -arch x86_64' -v
> :info:build ninja: error: unknown target 'CC=/opt/local/bin/clang-mp-8.0 -arch x86_64'
> :info:build Command failed:  cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_gnome_gtk3/gtk3/work/build-x86_64" && /opt/local/bin/ninja -j4 CC='/opt/local/bin/clang-mp-8.0 -arch x86_64' CC_FOR_BUILD='/opt/local/bin/clang-mp-8.0 -arch x86_64' -v
> :info:build Exit code: 1
> :error:build Failed to build gtk3: command execution failed
> :debug:build Error code: NONE
> :debug:build Backtrace: command execution failed
> :debug:build     while executing
> :debug:build "$procedure $targetname"
> :error:build See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_gnome_gtk3/gtk3/main.log for details.
>
>
>
> Lest anyone wonder, /opt/local/bin/clang-mp-8.0 does exist.

I note this is a universal build. The CC and CC_FOR_BUILD settings are 
part of a workaround intended to get g-ir-scanner to use the right 
compiler. They were removed from the non-universal case recently, I 
would assume because passing them in as build args like that doesn't 
work with meson, as seen above (and I wonder if g-ir-scanner is now 
using the wrong compiler again as a result). But they were left in the 
universal case. This is something the port maintainer needs to sort out.

<https://github.com/macports/macports-ports/commit/5dce2ee05f1275a3f720a8ab8eca3c7f8a656ee1>

- Josh