The GNUstep gui library is a library of graphical user interface classes written completely in the Objective-C language; the classes are based upon Apple's Cocoa framework (which came from the OpenStep specification). *** Larger patches require copyright assignment to FSF. please file bugs here. ***
Could there be other lingering undetected? I guess the issue is signed vs. unsigned enum, which is significative on 64Bit BE... on 32bit BE or 64BIT LE it doesn't caused issues.
Fix enum decoding issue of https://github.com/gnustep/libs-gui/issues/291