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Date: Sat, 6 Feb 2016 14:55:41 -0800 (PST)
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Subject: I do not understand this error...
From: John Smith <yoursurrogategod@gmail.com>
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Xref: news.eternal-september.org comp.lang.ada:29381
Date: 2016-02-06T14:55:41-08:00
List-Id: <comp.lang.ada>

Here is my code:
http://pastebin.com/JeR2VcXr
http://pastebin.com/PU65NmYB

It's a very simple gtk example that I copied just to mess with.  When I run 
"gprbuild", this is the error that I see:
$ gprbuild
using project file gtk_test.gpr
gcc -c -g gtk_test.adb
gtk_test.adb:16:04: instantiation error at gtk-handlers.ads:1039
gtk_test.adb:16:04: subprogram must not be deeper than access type
gtk_test.adb:17:04: instantiation error at gtk-handlers.ads:437
gtk_test.adb:17:04: subprogram must not be deeper than access type
gprbuild: *** compilation phase failed

Why?