>When a problem solver runs OS X, their options are severely limited, by design.
Hardly. On the surface, sure; that's part of the appeal. Underneath? GCC's a couple keystrokes away. There's even http://www.opensource.apple.com/ which has kernels[1] and lots of low-level code you can hack away at. Less than an OSS Unix distro? Absolutely. But not by all that far.
FWIW, the GCC, LD and other tools provided with OS X have a lot of deviations in terms of command line arguments and shared library path/bundle concepts.
You can have a simple application with a simple Makefile that works out of the box on any BSD and Linux system, but still have to adjust it to get it run under OS X.
So yes, under that hat OS X is some kind of Unix, but it is a very strange kind of Unix. OS X requires special cases in any build script, even in portable *.pro files of Qt projects.
So to me, as a developer and problem solver, OS X confronts me with a lot more distractions and nasty behavior than any other Unix-like system, including Windows+MinGW.
(This is because the MinGW cross compilers behave like normal GCC/Binutils as far as possible for the Windows platform. However, this solely because MinGW is developed by a group of volunteers, while the GCC functionality for OS X is developed by Apple. MinGW would surely look worse if it had been developed by Microsoft.)
A large part of that, from what I've encountered (by no means a representative sample), is due to Unix makefiles expecting/requiring X in specific-location-Y, or making things stringly-typed[1], or outright artificially restricting the systems it thinks it can run on, failing fake sanity checks up-front. Or other bad code.
But yes. OSX is not a direct match to other Unix-like systems, and a lot of source compiles not tweaked to handle OSX (many are) will require changing a couple things. Though Qt worked just fine for me, so who knows.
> A large part of that, from what I've encountered ...
Since I was talking about Makefile that run unmodified on any BSD and Linux, I'm clearly not talking about the kind of crappy build scripts you are mentioning. Those are an issue of their own.
> a lot of source compiles not tweaked to handle OSX
The problem is that you have to tweak scripts. You have to tweak even clean, simple scripts or libraries that use only portable constructs (i.e. without any hard-coded paths and other stupid stuff). And that's really nasty.
What experience is this based on? In my 6 years experience using a Mac as my primary machine, I've never had a higher rate of problems installing open source software with the default build scripts than on Linux.
Also, there's Macports, Fink, and Homebrew, which make it effortless.
This is always the major problem with Mac detractors. It's clear that they have little to no experience actually using a Mac for any extended period of time.
Hardly. On the surface, sure; that's part of the appeal. Underneath? GCC's a couple keystrokes away. There's even http://www.opensource.apple.com/ which has kernels[1] and lots of low-level code you can hack away at. Less than an OSS Unix distro? Absolutely. But not by all that far.
[1]: http://www.opensource.apple.com/source/xnu/xnu-1504.9.17/