cross-env-shell should be used since we are using variables in the command
This failed on Windows cmd:
C:\Users\xmr\Desktop\bootstrap>npm run css-prefix-examples-rtl
> bootstrap@5.0.0-alpha3 css-prefix-examples-rtl C:\Users\xmr\Desktop\bootstrap
> cross-env NODE_ENV=RTL postcss --config build/postcss.config.js --dir "site/content/docs/$npm_package_version_short/examples/" --ext ".rtl.css" --base "site/content/docs/$npm_package_version_short/examples/" "site/content/docs/$npm_package_version_short/examples/{blog,carousel,dashboard,cheatsheet}/*.css" "!site/content/docs/$npm_package_version_short/examples/{blog,carousel,dashboard,cheatsheet}/*.rtl.css"
Input Error: You must pass a valid list of files to parse