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From: AdaMagica <christ-usch.grein@t-online.de>
Newsgroups: comp.lang.ada
Subject: Re: Elaboration circularity with generics
Date: Sat, 14 Jan 2012 08:17:25 -0800 (PST)
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Date: 2012-01-14T08:17:25-08:00
List-Id: <comp.lang.ada>

A unit can only be instantiated if it is fully elaborated.
I guess GNAT chose the elaboration order P'Spec, P.Q'Spec, P'Body
(crash since P.Q'body is not elaborated).
This dependence is not present for nongeneric units.

Perhaps addition of pragma Elaborate_Body to P.Q helps.