[tex-live] tlmgr persistent downloads not working?

[Adam R. Maxwell]

I've noticed that tlmgr is spawning wget processes on my system when downloading updates.  I'm using Mac OS X, 10.6.4, MacTeX 2010, latest tlmgr:

$ tlmgr --version
tlmgr revision 20243 (2010-10-29 06:03:40 +0200)
tlmgr using installation: /usr/local/texlive/2010
TeX Live (http://tug.org/texlive) version 2010

Here's the command I tried, with debug output enabled (I snipped the rest, which is basically a long list of packages).  In spite of passing --persistent-downloads explicitly, it ends up using wget.  I've noticed this on a couple of different systems, with multiple mirrors, so it seems fairly consistent.  Has something changed in this regard recently?  

$ tlmgr update --list --persistent-downloads -v --repository http://mirror.unl.edu/ctan/systems/texlive/tlnet

D:Cannot open package log file /usr/local/texlive/2010/texmf-var/web2c/tlmgr.log for appending
D:Will not log package installation/removal/update for that run
D:persistent download are 1
D:Loading /usr/local/texlive/2010/tlpkg/texlive.tlpdb ...
D:Using shipped /usr/local/texlive/2010/tlpkg/installer/wget/wget.universal-darwin for wget (tested).
D:Using shipped /usr/local/texlive/2010/tlpkg/installer/xz/xzdec.universal-darwin for xzdec (tested).
D:Using shipped /usr/local/texlive/2010/tlpkg/installer/xz/xz.universal-darwin for xz (not tested).
tlmgr: package repository http://mirror.unl.edu/ctan/systems/texlive/tlnet
D:Loading http://mirror.unl.edu/ctan/systems/texlive/tlnet/tlpkg/texlive.tlpdb ...
D:TLPDB.pm: trying to initialize from http://mirror.unl.edu/ctan/systems/texlive/tlnet/tlpkg/texlive.tlpdb
D:trying to download http://mirror.unl.edu/ctan/systems/texlive/tlnet/tlpkg/texlive.tlpdb.xz to /var/folders/sG/sG+zlP062RWwfU+BYmcuyU+++TI/-Tmp-//texlive.tlpdb.32281.xz
D:downloading http://mirror.unl.edu/ctan/systems/texlive/tlnet/tlpkg/texlive.tlpdb.xz using /usr/local/texlive/2010/tlpkg/installer/wget/wget.universal-darwin --user-agent=texlive/wget --tries=10 --timeout=900 -q -O
D:download of http://mirror.unl.edu/ctan/systems/texlive/tlnet/tlpkg/texlive.tlpdb.xz succeeded
D:un-xzing /var/folders/sG/sG+zlP062RWwfU+BYmcuyU+++TI/-Tmp-//texlive.tlpdb.32281.xz to /var/folders/sG/sG+zlP062RWwfU+BYmcuyU+++TI/-Tmp-//texlive.tlpdb.32281
D:found the uncompressed xz file
D:Cannot save remote TeX Live database to /usr/local/texlive/2010/tlpkg/texlive.tlpdb.0872092f6696e877f0db8b140f6b82ef: Permission denied
D:Automatic backups activated, keeping 1 backups.
tlmgr: saving backups to /usr/local/texlive/2010/tlpkg/backups