libexec vs lib

[René J. V. Bertin]

Jeremy Huddleston Sequoia wrote:


>> Macports appears to install qt5-mac, llvm-3.5 and llvm-3.7 wholesale under
                               ^^^^^^^                        ^^^^^^^^^
Actually, that's a recent decision that ignored months of work I did on the Qt5 
port; I used ${prefix}/libexec/qt5 (and ${prefix}/libexec/qt4) only for the 
binary, version-specific files that weren't already installed in a version-
specific location (${prefix}/share/qt5 and ${prefix}/share/qt4). That is a 
scheme that is much closer to what is usual on Linux.

> If we want to come up with a standard location for subprefixes (eg:
> ${prefix}/opt), I'd be happy to switch to that.

I think that with so much of the ports in MacPorts coming from Linux (and/or 
Freedesktop, FOSS etc) it is strongly advisable to look at how things are done 
(laid out) there, and follow that lead. I sadly forgot to document the issues I 
had when I set out making qt4-mac coinstallable and at first put everything 
wholesale under ${prefix}/libexec/qt4 . I do remember though that I had a good 
reason to go back to the original layout and change only the locations that 
would cause conflict when a co-installed Qt5 (and which led to the layout I use 
currently). I cannot prove it therefore, but my hunch is that I ran into issues 
with shared resources that are also used by GTk/Gnome based ports (which have no 
a priori reason to use a subprefix at all).
Of course it's possible to do anything you'd want with ports that are mostly 
standalone like llvm+clang, but ports that interact with others (either directly 
or through their dependencies, like applications built on Qt) should not be 
moved around too lightheartedly, IMHO.

R.