/usr/share/GNUstep/Documentation/Developer/ is in gnustep-back-common 0.22.0-1ubuntu1.
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/usr/share/GNUstep/Documentation/Developer/Back/
/usr/share/GNUstep/Documentation/Developer/Back/General/
/usr/share/GNUstep/Documentation/Developer/Back/General/Back.html
/usr/share/GNUstep/Documentation/Developer/Back/General/DefaultsSummary.html
/usr/share/GNUstep/Documentation/Developer/Back/General/General.igsdoc
/usr/share/GNUstep/Documentation/Developer/Back/General/WindowFocus.html
/usr/share/GNUstep/Documentation/Developer/Back/General/dependencies
/usr/share/GNUstep/Documentation/Developer/Back/ReleaseNotes/
/usr/share/GNUstep/Documentation/Developer/Back/ReleaseNotes/0.22.0/
/usr/share/GNUstep/Documentation/Developer/Back/ReleaseNotes/0.22.0/ANNOUNCE
/usr/share/GNUstep/Documentation/Developer/Back/ReleaseNotes/0.22.0/INSTALL
/usr/share/GNUstep/Documentation/Developer/Back/ReleaseNotes/0.22.0/NEWS
/usr/share/GNUstep/Documentation/Developer/Back/ReleaseNotes/0.22.0/README