This is a CMake Environment Variable. Its initial value is taken from the calling process environment.
On UNIX one can use the
DESTDIR mechanism in order to relocate the
DESTDIR means DESTination DIRectory. It is
commonly used by makefile users in order to install software at
non-default location. It is usually invoked like this:
make DESTDIR=/home/john install
which will install the concerned software using the installation
/usr/local prepended with the
DESTDIR value which
DESTDIR may not be used on Windows because installation
prefix usually contains a drive letter like in
which cannot be prepended with some other prefix.