Next to the usual configuration script,
there is an alternative way to build xca.

At least on unix, one can use qmake to create a makefile
for building. Maybe this will help ,if you have a weired setup.

$ qmake -o makefile

creates the makefile. I recommend makefile to not overwrite Makefile
and also assures, that it is used instead of the original Makefile.

Now you need to create the file Local.h
$ cat >local.h <<EOF
> #define PREFIX "/usr/local"
> #define ETC "/etc/xca"
> #define VER "0.6.2"
> EOF

or you call ./configure to create it for you.

now just build XCA with

$ make