not compiling if two class declarations?

[damonteo]

hey, maybe a stupid question..

this compiles properly with ruby-sass but not with node-sass (gulp-sass):
.someclass {
@include sgs-change('gutter styles', 'opposite');
}

.someclass {
@include float-span(1);
}

Error:
WARNING: DEPRECATION: In order to remove global variable naming conflicts, Singularity's settings have been moved into the single $singularity variable. Please refer to our documentation (https://github.com/Team-Sass/Singularity/wiki) on how to update your settings. In the next version of Singularity, this warning will be removed. opposite has been returned.
Backtrace:
node_modules/singularitygs/stylesheets/singularitygs/helpers/_find.scss:37, in function find-object
node_modules/singularitygs/stylesheets/singularitygs/gutter-styles/_find.scss:14, in function find-gutter-style
node_modules/singularitygs/stylesheets/singularitygs/_api.scss:16, in mixin grid-span
node_modules/singularitygs/stylesheets/singularitygs/api/_float.scss:130, in mixin float-span
sass/base/_grids.scss:114, in mixin @content
node_modules/breakpoint-sass/stylesheets/_breakpoint.scss:66, in mixin breakpoint
sass/base/_grids.scss:15

however, this way it is compiling:
.someclass {
@include sgs-change('gutter styles', 'opposite');
@include float-span(1);
}

what am I missing?