Check the travis build: it seems that the travis build jumps into the LSSharedFileListItemCopyResolvedURL which obvisouly is not available < OSX 10.10 (travis builds with 10.7).
You might check your if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_10.

Testes on OSX 10.10. Build works fine.
Manipulating Startup-Flag works on 10.10.

Will build and test on 10.9 after you made Travis happy.

@jonasschnelli Can you please test on 10.9 even now? Maybe this is bug in how travis builds...

Just built on a official OSX 10.9. Works fine. No more warning.
Maybe the source problem lies here: https://opensource.apple.com/source/CarbonHeaders/CarbonHeaders-18.1/AvailabilityMacros.h

It doesn't look that the open-source implementations where up to date up till 10.9,10.10.

Tested on OSX 10.9 and 10.10.

ACK.

NACK. This needs to be a bit more complicated, I'm afraid.

There are a few things to keep in mind about the sdk versioning. Mainly, the SDK used for building, and the one used (by the user on a different machine) at runtime. To simplify, I'll expand on the two most extreme scenarios.

1. Building against the 10.10 sdk with -mmacosx-version-min=10.6. This allows for 10.10 functions to be used when possible while retaining compatibility with 10.6. However, these features may not be available if the user is running <10.10, so they need to be checked before use.
2. Building against the 10.6 sdk with no min version set. It doesn't know anything about 10.10 features, so support is never compiled in. It also has no idea what MAC_OS_X_VERSION_10_10 is.

We can build against 10.7 sdk (as we currently do for releases, with -mmacosx-version-min=10.6) such that old versions are still supported, and new features are used if they're detected at runtime. When we bump to newer SDKs or change mmacosx-version-min, everything continues to work as intended.

Something like this should cover all cases, I believe (untested, may need an AvailabilityMacros.h include):

#ifndef NSAppKitVersionNumber10_10
#define NSAppKitVersionNumber10_10 1343
#endif

#if defined(MAC_OS_X_VERSION_MAX_ALLOWED)
  #if MAC_OS_X_VERSION_MAX_ALLOWED < 10100
    // Built using < 10.10 sdk
    LSSharedFileListItemResolve(item, resolutionFlags, &currentItemURL, NULL);
  #else
    // Built using >= 10.10 sdk and detected >= 10.10 at runtime
    if (floor(NSAppKitVersionNumber) >= NSAppKitVersionNumber10_10)
        currentItemURL = LSSharedFileListItemCopyResolvedURL(item, resolutionFlags, NULL);
    #if MAC_OS_X_VERSION_MIN_REQUIRED < 10100
    else // Built using >= 10.10 sdk with back-compat and detected < 10.10 at runtime
        LSSharedFileListItemResolve(item, resolutionFlags, &currentItemURL, NULL);
    #endif
  #endif
#endif

Uh. Thanks cfields! You totally right.

If you need all that crazyness just to work around a deprecation warning...

@cfields Uff, yes.
There should be a #else branch for !defined MAC_OS_X_VERSION_MAX_ALLOWED.
So the question is how complicated we want this to be...
@wumpus right now, it is deprecation warning, but after a few months/years, our code won't run on all systems and we have to handle run time compatibility anyway.

But it is not fun, I agree ;-)

I'm looking forward to when we can drop 10.6 compat, and just set 10.7 as the minimum osx.

Not the right wumpus!

@wumpus Greg Lindahl / could you please stop spamming. Thanks.
Incident has been reported to Github.

Huh, spamming? Mr wumpus was just replying because @paveljanik highlighted the wrong person. He's the one that should stand in the corner, if anyone :)

@laanwj Yes. Sorry. IRC/Github mix.

OK, @cfields's version used.

Travis OK.
OS X 10.10 OK.

OS X 10.9 OK too.

@paveljanik Following up from the recent SDK changes, cfields has suggested a new patch.

#if defined(MAC_OS_X_VERSION_MAX_ALLOWED) && MAC_OS_X_VERSION_MAX_ALLOWED >= 10100
  if(&LSSharedFileListItemCopyResolvedURL)
    currentItemURL = LSSharedFileListItemCopyResolvedURL(item, resolutionFlags, NULL);
  else
#endif
    currentItemURL = LSSharedFileListItemResolve(item, resolutionFlags, &currentItemURL, NULL);

After looking at that again, we'd still get the deprecation warning with the above code. One more try:

#if defined(MAC_OS_X_VERSION_MAX_ALLOWED) && MAC_OS_X_VERSION_MAX_ALLOWED >= 10100
  if(&LSSharedFileListItemCopyResolvedURL)
    currentItemURL = LSSharedFileListItemCopyResolvedURL(item, resolutionFlags, NULL);
  #if defined(MAC_OS_X_VERSION_MIN_REQUIRED) && MAC_OS_X_VERSION_MIN_REQUIRED < 10100
  else
    currentItemURL = LSSharedFileListItemResolve(item, resolutionFlags, &currentItemURL, NULL);
  #endif
#else
  currentItemURL = LSSharedFileListItemResolve(item, resolutionFlags, &currentItemURL, NULL);
#endif

Updated.

fixed the wrong assignment, waiting for Travis.

Builds without warning now on Travis and native OS X 10.10.