fltk 1.3.2 failed to build on 10.10

[vlnk]

hi,
gisted logs: https://gist.github.com/fc8638080729030e8870

maybe, it's the same issue of #29988

relevant part of log:

=== installing FL ===
Installing include files in /usr/local/Cellar/fltk/1.3.2_1/include...
=== installing src ===
Compiling Fl_cocoa.mm...
Compiling Fl_Quartz_Printer.mm...
Compiling Fl_Native_File_Chooser_MAC.mm...
Compiling Fl.cxx...
Compiling Fl_Adjuster.cxx...
Fl_cocoa.mm:1325:24: error: cannot initialize a parameter of type 'id<NSFileManagerDelegate>' with an rvalue of type 'FLDelegate *'
    [NSApp setDelegate:[[FLDelegate alloc] init]];
                       ^~~~~~~~~~~~~~~~~~~~~~~~~
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/usr/include/objc/NSObject.h:60:1: note: instance method 'init' is assumed to return an instance of its receiver type ('FLDelegate *')
- (instancetype)init;
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSFileManager.h:109:47: note: passing argument to parameter 'delegate' here
@property (assign) id <NSFileManagerDelegate> delegate NS_AVAILABLE(10_5, 2_0);
                                              ^
Fl_cocoa.mm:2234:21: error: cannot initialize a parameter of type 'id<NSWindowDelegate>' with an rvalue of type 'id<NSFileManagerDelegate>'
    [cw setDelegate:[NSApp delegate]];
                    ^~~~~~~~~~~~~~~~
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/System/Library/Frameworks/AppKit.framework/Headers/NSWindow.h:307:41: note: passing argument to parameter 'delegate' here
@property (assign) id<NSWindowDelegate> delegate;
                                        ^
Compiling Fl_Bitmap.cxx...
2 errors generated.
make[1]: *** [Fl_cocoa.o] Error 1
make[1]: *** Waiting for unfinished jobs....
make: *** [install] Error 1

HOMEBREW_VERSION: 0.9.5
HEAD: f8c1116599ac69be6308796cdabdc620dd72f1d0
CPU: quad-core 64-bit haswell
OS X: 10.10-x86_64
Xcode: 6.0.1
X11: 2.7.7 => /opt/X11

[jacknagel]

fltk is known to fail on 10.10; see #29988