The first step in each of these build procedures is to unpack the source distribution. The Kerberos V5 distribution comes in a tar file, generally named krb5-post-1.4.tar, which contains a compressed tar file consisting of the sources for all of Kerberos (generally krb5-post-1.4.tar.gz) and a PGP signature for this source tree (generally krb5-post-1.4.tar.gz.asc). MIT highly recommends that you verify the integrity of the source code using this signature.
Unpack the compressed tar file in some directory, such as /u1/krb5-post-1.4. (In the rest of this document, we will assume that you have chosen to unpack the Kerberos V5 source distribution in this directory. Note that the tarfiles will by default all unpack into the ./krb5-post-1.4 directory, so that if your current directory is /u1 when you unpack the tarfiles, you will get /u1/krb5-post-1.4/src, etc.)