Building from source in Windows 10 (build_ui.sh command not found)

I am trying to build Prometheus.io from source in Windows 10 according to the instructions. Unfortunately i come across the following error via Cygwin after using
make build config.file prometheus.yml.

prometheus-io@0.46.0 build
set "GENERATE_SOURCEMAP=false" && bash build_ui.sh --all

build_ui.sh: line 2: $'\r': command not found
build_ui.sh: line 15: $'\r': command not found
: invalid optione 16: set: -
set: usage: set [-abefhkmnptuvxBCEHPT] [-o option-name] [--] [-] [arg ...]
build_ui.sh: line 17: $'\r': command not found
build_ui.sh: line 18: syntax error in conditional expression
make: *** [ui-build] Error 127

after updating the package.json from "build": "GENERATE_SOURCEMAP=false bash build_ui.sh --all",
to "build": "set \"GENERATE_SOURCEMAP=false\" && bash build_ui.sh --all",

I think that a .bat file should replace the respective build_ui.sh, but i am not sure of its contents. It would help me a lot, if anyone has built it before via Windows .

Regards