Empty CSS classes lost in postcss-nested & postcss-modules -

i have css i'm trying compile postcss, postcss-nested , postcss-modules:

.foo {   &__bar {     color: red;   } }

i want compile , use postcss-modules classes out of it, should output:

{  foo: 'hash',  foo__bar: 'hash', }

the problem plugin going output only:

.foo__bar { color: red; }

and postcss-modules isn't able extract .foo, exposing only:

{  foo__bar: 'hash', }

i noticed isn't problem if use webpack , css-loader (with ?modules&importloaders=1) it's problem if use barebones postcss.

ideas?

RT