The confBUILDBIN macro is used to define the location of the devtools/bin directory. Normally, this macro will never have to be defined because the default value is correct, but there might be a rare circumstance when you will need to redefine it. If, for example, you need to move the devtools/bin directory to a different path, or rename it, you can do so like this:

define(`confBUILDBIN', `../../OLD_devtools/bin')

Note that the value given to confBUILDBIN must be either an absolute path or a path relative to the obj directory (sendmail is built inside the obj directory).

The confBUILDBIN macro sets the BUILDBIN= line in Makefile. Depending on your operating system, that line might or might not be used. For Solaris 2.5, for example, it is used like this:

INSTALL=${BUILDBIN}/install.sh

One use for confBUILDBIN can occur when you are actively modifying the sendmail code, and it becomes appropriate to maintain the source completely separate from the normal distribution tree.