Rebuild the library with Windows, GTK+ 2.x or Cocoa support

Rebuilding a library with Windows, GTK+ 2.x, or Cocoa support means porting the library to work on these different platforms. Here's a brief explanation:

1. **Windows**: To rebuild for Windows, you'd need to compile the library using platform-specific tools such as Microsoft Visual Studio or mingw (GCC compiler for Windows). This typically involves adapting code to use Win32 APIs, handling GUI components with libraries like wxWidgets if the library doesn't have native support.

2. **GTK+ 2.x**: If your library targets GTK+, it would require integration with the GTK+ toolkit, which provides a set of widgets and APIs for creating graphical user interfaces on Linux and other Unix-like systems. You'll need to modify the code to adhere to GTK+ standards and utilize its widget system.

3. **Cocoa**: For Cocoa support in macOS, the library would need to be recompiled against Apple's frameworks, specifically AppKit or SwiftUI. This involves converting Objective-C or C++ code to work with Cocoa objects and event handling.

In each case, developers may need to update Makefiles, configure scripts, or use platform-specific build tools to ensure that the library compiles correctly and functions seamlessly on the chosen platform.