The Mac exporter in XCode Project mode doesn't work for extensions with spaces in their filenames.
Works fine for Mac Application.
It's a simple fix: in the pbxproj, surround the filename in double-quotes.
Code:
/* Begin PBXFileReference section */
/* broken */
EC37308CD480B21176A44F91 /* SDL Object.bundle */ = {isa = PBXFileReference; lastKnownFileType = "wrapper.plug-in"; name = SDL Object.bundle; path = Resources/SDL Object.bundle; sourceTree = "<group>"; };
/* OK */
EC37308CD480B21176A44F91 /* SDL Object.bundle */ = {isa = PBXFileReference; lastKnownFileType = "wrapper.plug-in"; name = "SDL Object.bundle"; path = "Resources/SDL Object.bundle"; sourceTree = "<group>"; };
0465DE021C2989F3003887BF /* default.fsh */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.glsl; name = default.fsh; path = Resources/Shaders/default.fsh; sourceTree = "<group>"; };
This may affect more than just exts, but I've not checked.