Installing Octave on Snow Leo

[Ryan Schmidt]

On Jan 20, 2018, at 14:55, Uli Wienands wrote:

> Ok, I did selfupdate Macports and tried again, and indeed it now gets past this hurdle.
> 
> However, at the end it tells me that all compilers are blacklisted & it will default to first fall-back option (whatever that is)_. It then wants to install clang 5.0 and llvm 5.0, at which time I said "no" and let the thing terminate. I really don't want to install another compiler. I have gcc up to 7 and I don't think clang works particularly well with Snow Leo. (I also don't think clang 5 would build on Snow Leo).
> 
> Tracking this down a little further, it seems that qscintilla-qt4 is unhappy with my compilers. Trying to install it separately using macport's gcc-6 bombs as gcc-6 does not seem to understand a flag like -Xarch=64 (or something like this; the log file got clobbered since).
> 
> Looking into the portfile for qscintilla-qt4, but I cannot see where it blacklists compilers. 
> 
> Does anyone know how to comple scintilla-qt4 using gcc? Seems hard to believe this does not work (the same install worked beautifully on a Raspberry Pi not long ago).
> 
> Thanks for you help so far

clang works great on Intel Macs, including on Snow Leopard. We have pre-compiled binaries of clang-5.0 on Snow Leopard so it builds fine.

When all compilers are blacklisted, MacPorts falls back to the first compiler, which on Snow Leopard is gcc-4.2. But because it was blacklisted the port is expected to fail to compile.

However, we have a bug in MacPorts where we are blacklisting overzealously in situations where C++11 and therefore libc++ is needed, such that although MacPorts states that all compilers are blacklisted, in fact the port should build with one of them. That's what's happening with qscintilla-qt4, since it includes the cxx11 1.1 portgroup. We need to fix this bug and release a new version of MacPorts. See https://trac.macports.org/ticket/55444

Unless a port is configured to build using MacPorts gcc, please don't attempt to build a port with MacPorts gcc on an Intel Mac; we don't want to help you with all of the problems you will encounter as a result of doing that. Ports should install without needing to override MacPorts' compiler selection; if not, file a bug.