pkg update breaks pkg system

[Nelson H. F. Beebe]

Antonio asks:

>> What is the error you're getting? Only the lua one?

There was both the issue of two missing libraries (solved by temporary
symlinks), and this lua failure:

	# pkg install sudo
	...
	1/1] Installing sudo-1.9.3p1...
	[1/1] Extracting sudo-1.9.3p1: 100%
	pkg: Failed to execute lua script: [string "args = {}..."]:11:
	attempt to call a nil value (field 'stat')
	pkg: lua script failed

It seems to me that the packaging system must have errors in its
dependencies for the package named "pkg": it should not have been
possible to install pkg-1.15.10 unless its dependent libraries were
downloaded and installed first.

The Lua versions are these:

	# /usr/local/bin/lua54 -v
	Lua 5.4.1  Copyright (C) 1994-2020 Lua.org, PUC-Rio

	# /usr/local/bin/luac54 -v
	Lua 5.4.1  Copyright (C) 1994-2020 Lua.org, PUC-Rio

Unfortunately, pkg reports "lua script failed", but does not identify
the name of the failing script, which is another serious flaw in pkg.

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- Nelson H. F. Beebe                    Tel: +1 801 581 5254                  -
- University of Utah                    FAX: +1 801 581 4148                  -
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