The version of sudo that ships with Debian by default resets the
environment, as described by the "env_reset" flag in the sudoers file.

This implies that all environment variables are removed, except for
LOGNAME, PATH, SHELL, TERM, DISPLAY, XAUTHORITY, XAUTHORIZATION, XAPPLRESDIR, 
XFILESEARCHPATH, XUSERFILESEARCHPATH, LANG, LANGUAGE, LC_*, and USER.

In case you want sudo to preserve more environment variables, you must
specify the env_keep variable in the sudoers file. You should edit the
sudoers file using the visudo tool.

Examples:
Preserve the default variables plus the EDITOR variable:

    Defaults env_keep+="EDITOR"

Preserve the default variables plus all variables starting with LC_:

    Defaults env_keep+="LC_*"

	- - - - -

If you're using the sudo-ldap package, note that it is now configured to 
look for /etc/sudo-ldap.conf.  Depending on your system configuration, it
probably makes sense for this to be a symlink to /etc/ldap.conf, or perhaps
to /etc/libnss-ldap.conf or /etc/pam_ldap.conf.  By default, no symlink or
file is provided, you'll need to decide what to do and create a suitable
file before sudo-ldap will work.

	- - - - -

As of version 1.7, sudo-ldap now requires the LDAP source to be specified
in /etc/nsswitch.conf with a line like:

  sudoers:	ldap

	- - - - -

See the file OPTIONS in this directory for more information on the sudo
build options used in building the Debian package.

	- - - - -

If you're having trouble grasping the fundamental idea of what sudo is all
about, here's a succinct and humorous take on it...   

	http://www.xkcd.com/c149.html

