When using d-i etch rc2, apt-setup will fail if the mirror you are
trying to use does not have a "testing" symlink available. In rc1 and
before, it would find the codename directly. Here is what seems to be
the relevant section of syslog during install:
Mar 27 22:58:25 apt-setup: Reading package lists...
Mar 27 22:58:53 choose-mirror[24308]: DEBUG: command: wget -q http://my.mirror/debian//dists/testing/Release -O - | grep ^Suite: | cut -d' ' -f 2
Mar 27 22:58:53 choose-mirror[24308]: DEBUG: command: wget -q http://my.mirror/debian//dists/etch/Release -O - | grep ^Suite: | cut -d' ' -f 2
Mar 27 22:58:53 choose-mirror[24308]: DEBUG: command: wget -q http://my.mirror/debian//dists/testing/Release -O - | grep ^Codename: | cut -d' ' -f 2
Mar 27 22:58:54 choose-mirror[24308]: ERROR **: Error getting codename
Mar 27 22:58:54 apt-setup: warning: /usr/lib/apt-setup/generators/50mirror returned error code 1; discarding output
On the businesscard CD, this is a fatal error and installation cannot
continue. That by itself would be a minor annoyance to me (since it's
a private mirror that I could just set the symlink on), but on the
netinst CD, this is a silent error, and only the cdrom and security.d.o
are put into sources.list. As a result, only "Laptop" and "Standard
System" are given by tasksel on the next step, and a half-broken system
is installed (just what packages happen to be on security.d.o).
RF