gulp-sass missing some functionalities - npm

Question

I'm starting to work on an ongoing development with gulp and sass.
The workflow was set up for someone not avaialable at the momment and it has been working for people on the team.
Sass compiles on other people machines but not on mine.
I do compile sass on my machine in dozens of other projects without problem but not on this particular one.
I think I did initialize the project correctly but I suspect there is some version or configuration problem involved.
If I npm install everything and run gulp I get the following error:
Error: src/sass/utilities/mixins/_vendor-prefixes.scss
Error: Invalid CSS after "::-webkit-": expected "{", was "&-placeholder"
"&-placeholder" may only be used at the beginning of a compound selector.
on line 116 of src/sass/utilities/mixins/_vendor-prefixes.scss
I tried commenting the offending lines and running gulp again just to stumble with another error:
Error: src/sass/base/_base.scss
Error: "ul" failed to #extend "%reset-list".
The selector "%reset-list" was not found.
Use "#extend %reset-list !optional" if the extend should be able to fail.
on line 142 of src/sass/base/_base.scss
And so on:
Error: src/sass/utilities/_placeholders.scss
Error: You may not #extend an outer selector from within #media.
You may only #extend selectors within the same directive.
From "#extend %clearfix" on line 38 of src/sass/modules/_calendar.scss
on line 9 of src/sass/utilities/_placeholders.scss
This code works on other machines and all that advanced selector are being used on the development.
If I google for the particular errors I can find errors about them and people suggesting alternate selectors but I suspect that there is something else going on that I should fix.
I have updated my gulp to 3.9.1 and gulp-sass to 3.1.0 but I get the same errors.
How should I debug this?
Thanks!
EDIT: The errors are clearly stating that the code is not valid but the strange thing is that the same code is working on other peoples machines.
I'll post some code arround some of the errors just for reference anyway:
_vendor-prefixes.scss:116
// Placeholder focus text
#mixin placeholder-focus($color: $input-color-placeholder) {
&:focus::-webkit-&-placeholder { color:$color; }
&:focus:-moz-placeholder { color:$color; } /* FF 4-18 */
&:focus::-moz-placeholder { color:$color; } /* FF 19+ */
&:focus:-ms-input-placeholder { color:$color; }
}
_base.scss:142
// Unordered and Ordered lists
ul,
ol {
#extend %reset-list;
}
and the include on _placeholders.scss
// Reset List
%reset-list {
padding:0;
margin:0;
li {
list-style:none;
}
}

Answer 1

This had nothing to do with functionalities or versions.
As #rac pointed out the code is invalid.
The other developer was skiping the errors somehow and the compiled .css did not have the faulty lines or the faulty extends.
Removing all the faulty lines resulted in the same .css and a clean compile.
Thanks!