installing libpam-unix2 on clean karmic machine locks out all users

[swaddo]

Binary package hint: libpam-unix2

installing the libpam-unix2 package alone is sufficient to completely lock out all users in Karmic

major problem when installing a package that depends on this package. included below is a log showing the failure (removing the package again is sufficient to again grant access to all users.

details:
ubuntu version: Ubuntu 9.10
package: /libpam-unix2_1%3a2.4.1-4_i386.deb ... (%3a ?)
expected behavior: users are still able toa ccess machine
actual behavior. All password authentication seems to be blocked. No users can authenticate.

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root@www1:/etc/pam.d# apt-get install libpam-unix2
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
  php-xml-serializer php-xml-parser libreadline5 libnusoap-php
Use 'apt-get autoremove' to remove them.
The following NEW packages will be installed:
  libpam-unix2
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 0B/81.9kB of archives.
After this operation, 791kB of additional disk space will be used.
Selecting previously deselected package libpam-unix2.
(Reading database ... 132147 files and directories currently installed.)
Unpacking libpam-unix2 (from .../libpam-unix2_1%3a2.4.1-4_i386.deb) ...
Processing triggers for man-db ...
Setting up libpam-unix2 (1:2.4.1-4) ...
root@www1:/etc/pam.d# su - blake
blake@www1:~$ sudo -i
[sudo] password for blake:
Sorry, try again.
[sudo] password for blake:

session transcript showing how to replicate ...
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root@www1:/etc/pam.d# apt-get install libpam-unix2
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
  php-xml-serializer php-xml-parser libreadline5 libnusoap-php
Use 'apt-get autoremove' to remove them.
The following NEW packages will be installed:
  libpam-unix2
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 0B/81.9kB of archives.
After this operation, 791kB of additional disk space will be used.
Selecting previously deselected package libpam-unix2.
(Reading database ... 132147 files and directories currently installed.)
Unpacking libpam-unix2 (from .../libpam-unix2_1%3a2.4.1-4_i386.deb) ...
Processing triggers for man-db ...
Setting up libpam-unix2 (1:2.4.1-4) ...
root@www1:/etc/pam.d# su - blake
blake@www1:~$ sudo -i
[sudo] password for blake:
Sorry, try again.
[sudo] password for blake:

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[Mårten Björklund (marten-fantastiskt)]

I can confirm this bug on fresh installs of 10.04 amd64 and 10.10 amd64