xaos: restrict compilers to supported by qt64

[tuffnatty]

Description

Building xaos on Mojave fails, as it tries to use the unsupported XCode 10.3 compiler.
Add the needed compiler.blacklist-append directive.

Type(s)

• bugfix
• enhancement
• security fix

Tested on

macOS 10.14.6 18G9323 x86_64
Command Line Tools 10.3.0.0.1.1562985497

Verification

Have you

• followed our Commit Message Guidelines?
• squashed and minimized your commits?
• checked that there aren't other open pull requests for the same change?
• referenced existing tickets on Trac with full URL in commit message?
• checked your Portfile with port lint?
• tried existing tests with sudo port test?
• tried a full install with sudo port -vst install?
• tested basic functionality of all binary files?
• checked that the Portfile's most important variants haven't been broken?

[szhorvat]

Thanks for fixing this!

If this is necessary for Qt 6.4, shouldn't it be done by the Qt6 port group?

[tuffnatty]

@szhorvat Probably you are right, but I am not sure what's the usual practice. I see other PortGroups are blacklisting compiler versions, probably qt6 could also do this. So you're proposing to move it to the port group?

[reneeotten]

why would this need the same compiler as Qt 6.4 ; what is the error you're seeing if this is not set? I am pretty sure there is no need to set anything in the qt6 PortGroup for this as I fail to see why it would be related to what compiler Qt6 used.

[tuffnatty]

@reneeotten Because it uses Qt 6 headers, and they are not compatible with Apple Clang < 1100:

In file included from /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_graphics_xaos/xaos/work/XaoS-4.3.3/src/ui-hlp/ui_helper.cpp:13:
In file included from /opt/local/libexec/qt6/lib/QtGui.framework/Headers/qclipboard.h:7:
In file included from /opt/local/libexec/qt6/lib/QtGui.framework/Headers/qtguiglobal.h:7:
In file included from /opt/local/libexec/qt6/lib/QtCore.framework/Headers/qglobal.h:98:
/opt/local/libexec/qt6/lib/QtCore.framework/Headers/qcompilerdetection.h:128:10: error: "Unsupported Apple Clang version"
#        error "Unsupported Apple Clang version"
         ^
/opt/local/libexec/qt6/lib/QtCore.framework/Headers/qcompilerdetection.h:844:4: error: "Qt6 requires Unicode string support in both the compiler and the standard library"
#  error "Qt6 requires Unicode string support in both the compiler and the standard library"
   ^
...
In file included from /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_graphics_xaos/xaos/work/build/XaoS_autogen/mocs_compilation.cpp:2:
In file included from /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_graphics_xaos/xaos/work/build/XaoS_autogen/YPKJ5OE7LN/moc_customdialog.cpp:10:
In file included from /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_graphics_xaos/xaos/work/build/XaoS_autogen/YPKJ5OE7LN/../../../XaoS-4.3.3/src/ui/customdialog.h:4:
In file included from /opt/local/libexec/qt6/lib/QtWidgets.framework/Headers/QDialog:1:
In file included from /opt/local/libexec/qt6/lib/QtWidgets.framework/Headers/qdialog.h:7:
In file included from /opt/local/libexec/qt6/lib/QtWidgets.framework/Headers/qtwidgetsglobal.h:7:
In file included from /opt/local/libexec/qt6/lib/QtGui.framework/Headers/qtguiglobal.h:7:
In file included from /opt/local/libexec/qt6/lib/QtCore.framework/Headers/qglobal.h:1403:
In file included from /opt/local/libexec/qt6/lib/QtCore.framework/Headers/qatomic.h:10:
/opt/local/libexec/qt6/lib/QtCore.framework/Headers/qbasicatomic.h:21:4: error: "Qt requires C++11 support"
#  error "Qt requires C++11 support"
   ^

[tuffnatty]

@reneeotten Thanks! So you don't support the idea this should be at the PortGroup level? Because I suspect there are many more qt6 dependents needing this.