running configure, build, and destroot phases twice in a single port?

[Adam Mercer]

Hi

I'd like to revisit an old issue and see how the fftw-3 and
fftw-3-single ports can be merged into a single port (and also for
fftw and fftw-single). There are several software packages that
require that both the single and double precision builds of the
library need to be available at the same time so using a variant is
not an option. Therefore the merged port would need to run the
configure, build, and destroot phases twice (with slightly different
configuration options).

Is there an existing port that does this? Or does anyone know of a way
this can be done?

Cheers

Adam