Serenity:~/pure-ftpd-1.0.21# apt-get install build-essential
Reading Package Lists... Done
Building Dependency Tree... Done
Package build-essential is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
W: Couldn't stat source package list http://http.us.debian.org stable/main Packages (/var/lib/apt/lists/http.us.debian.org_debian_dists_stable_main_binary-i386_Packages) - stat (2 No such file or directory)
W: Couldn't stat source package list http://http.us.debian.org stable/contrib Packages (/var/lib/apt/lists/http.us.debian.org_debian_dists_stable_contrib_binary-i386_Packages) - stat (2 No such file or directory)
W: Couldn't stat source package list http://http.us.debian.org stable/non-free Packages (/var/lib/apt/lists/http.us.debian.org_debian_dists_stable_non-free_binary-i386_Packages) - stat (2 No such file or directory)
W: Couldn't stat source package list http://non-us.debian.org stable/non-US/main Packages (/var/lib/apt/lists/non-us.debian.org_debian-non-US_dists_stable_non-US_main_binary-i386_Packages) - stat (2 No such file or directory)
W: Couldn't stat source package list http://non-us.debian.org stable/non-US/contrib Packages (/var/lib/apt/lists/non-us.debian.org_debian-non-US_dists_stable_non-US_contrib_binary-i386_Packages) - stat (2 No such file or directory)
W: Couldn't stat source package list http://non-us.debian.org stable/non-US/non-free Packages (/var/lib/apt/lists/non-us.debian.org_debian-non-US_dists_stable_non-US_non-free_binary-i386_Packages) - stat (2 No such file or directory)
W: Couldn't stat source package list http://security.debian.org stable/updates/contrib Packages (/var/lib/apt/lists/security.debian.org_dists_stable_updates_contrib_binary-i386_Packages) - stat (2 No such file or directory)
W: Couldn't stat source package list http://security.debian.org stable/updates/non-free Packages (/var/lib/apt/lists/security.debian.org_dists_stable_updates_non-free_binary-i386_Packages) - stat (2 No such file or directory)
W: Couldn't stat source package list http://http.us.debian.org stable/main Packages (/var/lib/apt/lists/http.us.debian.org_debian_dists_stable_main_binary-i386_Packages) - stat (2 No such file or directory)
W: Couldn't stat source package list http://http.us.debian.org stable/contrib Packages (/var/lib/apt/lists/http.us.debian.org_debian_dists_stable_contrib_binary-i386_Packages) - stat (2 No such file or directory)
W: Couldn't stat source package list http://http.us.debian.org stable/non-free Packages (/var/lib/apt/lists/http.us.debian.org_debian_dists_stable_non-free_binary-i386_Packages) - stat (2 No such file or directory)
W: Couldn't stat source package list http://non-us.debian.org stable/non-US/main Packages (/var/lib/apt/lists/non-us.debian.org_debian-non-US_dists_stable_non-US_main_binary-i386_Packages) - stat (2 No such file or directory)
W: Couldn't stat source package list http://non-us.debian.org stable/non-US/contrib Packages (/var/lib/apt/lists/non-us.debian.org_debian-non-US_dists_stable_non-US_contrib_binary-i386_Packages) - stat (2 No such file or directory)
W: Couldn't stat source package list http://non-us.debian.org stable/non-US/non-free Packages (/var/lib/apt/lists/non-us.debian.org_debian-non-US_dists_stable_non-US_non-free_binary-i386_Packages) - stat (2 No such file or directory)
W: Couldn't stat source package list http://security.debian.org stable/updates/contrib Packages (/var/lib/apt/lists/security.debian.org_dists_stable_updates_contrib_binary-i386_Packages) - stat (2 No such file or directory)
W: Couldn't stat source package list http://security.debian.org stable/updates/non-free Packages (/var/lib/apt/lists/security.debian.org_dists_stable_updates_non-free_binary-i386_Packages) - stat (2 No such file or directory)
W: You may want to run apt-get update to correct these problems
E: Package build-essential has no installation candidate