libFoundation removal and hg/git hiccup

[Taylor R Campbell <campbell+netbsd-tech-pkg%mumble.net@localhost>]

The removal of devel/libFoundation on 2023-01-13 appeared to trigger a
forced-update in the git mirror (and presumably hg).

The only change to the history in the forced-update is this (diff is
-from old history, before forced update; +to new history, after forced
update):

+diff --git a/devel/libFoundation/patches/patch-aa b/devel/libFoundation/patches/patch-aa
+index 9dbcf69e59ec..631e0c9979e3 100644
+--- a/devel/libFoundation/patches/patch-aa
++++ b/devel/libFoundation/patches/patch-aa
+@@ -1,13 +1,13 @@
+-$NetBSD: patch-aa,v 1.1 2009/04/18 02:19:23 rh Exp $
++$NetBSD: patch-aa,v 1.1.1.1 2009/04/18 02:27:21 rh Exp $                     
+
+---- GNUmakefile.orig  2009-04-18 10:49:03.000000000 +1000                    
++--- GNUmakefile.orig  2009-04-18 11:56:31.000000000 +1000                    
+ +++ GNUmakefile
+ @@ -38,7 +38,7 @@ GNUSTEP_INSTALLATION_DOMAIN = SYSTEM                       
+  include $(GNUSTEP_MAKEFILES)/common.make                                    
+  include ./Version
+
+ -SUBPROJECTS = Foundation Resources examples                                 
+-+SUBPROJECTS = Foundation Resources
+++SUBPROJECTS = examples
+
+  include $(GNUSTEP_MAKEFILES)/aggregate.make                                 
+
... [no further changes here]
+
+Author: wiz <wiz%pkgsrc.org@localhost>
+Date:   Fri Jan 13 12:39:59 2023 +0000
+
+    libFoundation*: remove
+
+    No upstream since 2008, no users in pkgsrc

devel/libFoundation/patches/patch-aa was originally created in this
commit:

Author: rh <rh%pkgsrc.org@localhost>
Date:   Sat Apr 18 02:19:23 2009 +0000

    Update libFoundation to 1.1.7.168.  This makes libFoundation play nice with
    the new gnustep-make directory structure.  Other notable changes include:
     * bugfixes and stability improvements
     * Support for some new Cocoa classes, like NSURL
     * Improved compatibility with gstep-base
     * more and fixed timezone files
     * support for read-only strings in UTF-8 and UTF-16
     * some fixes for warnings thrown in new gcc (gcc3+) compilers

In the old history, before the forced-update, that was it -- no
further changes to patch-aa.  But in the new history, after the
forced-update, patch-aa got changed from rev. 1.1 to rev. 1.1.1.1 in
the following commit:

Author: rh <rh%pkgsrc.org@localhost>
Date:   Sat Apr 18 02:27:21 2009 +0000

    Initial import of libFoundation-examples-1.1.7.168.  This package contains 
    the split-out examples from libFoundation.                                 
...
@@ -1,13 +1,13 @@
-$NetBSD: patch-aa,v 1.1 2009/04/18 02:19:23 rh Exp $                          
+$NetBSD: patch-aa,v 1.1.1.1 2009/04/18 02:27:21 rh Exp $                      
...
-+SUBPROJECTS = Foundation Resources
++SUBPROJECTS = examples

Why did removing devel/libFoundation have this effect?  What can we
do to avoid this kind of disruption in the future, other than
permanently migrating from CVS?