/usr/share/GNUstep/Documentation/Developer/Gui/Additions/ is in gnustep-gui-doc 0.24.0-3.
This file is owned by root:root, with mode 0o755.
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/usr/share/GNUstep/Documentation/Developer/Gui/Additions/ClassesTOC.html
/usr/share/GNUstep/Documentation/Developer/Gui/Additions/Functions.html
/usr/share/GNUstep/Documentation/Developer/Gui/Additions/FunctionsTOC.html
/usr/share/GNUstep/Documentation/Developer/Gui/Additions/GSDisplayServer.html
/usr/share/GNUstep/Documentation/Developer/Gui/Additions/GSHbox.html
/usr/share/GNUstep/Documentation/Developer/Gui/Additions/GSTable.html
/usr/share/GNUstep/Documentation/Developer/Gui/Additions/GSTheme.html
/usr/share/GNUstep/Documentation/Developer/Gui/Additions/GSVbox.html
/usr/share/GNUstep/Documentation/Developer/Gui/Additions/GuiAdditions.html
/usr/share/GNUstep/Documentation/Developer/Gui/Additions/MainIndex.html
/usr/share/GNUstep/Documentation/Developer/Gui/Additions/OrderedSymbolDeclarations.plist
/usr/share/GNUstep/Documentation/Developer/Gui/Additions/TypesAndConstants.html
/usr/share/GNUstep/Documentation/Developer/Gui/Additions/TypesTOC.html
/usr/share/GNUstep/Documentation/Developer/Gui/Additions/VariablesTOC.html
/usr/share/GNUstep/Documentation/Developer/Gui/Additions/index.html