Rudder

If you try to use file_download.cf without curl or wget installed, it provides a nice report:

R: [ERROR] Promise could not be repaired, error encountered: Unable to download http://www.normation.com/robots.txt: neither wget or curl are installed

However, http_request_check_status_headers fails without a clear explanation:

   error: Command related to promiser '${paths.path[curl]}' returned code defined as promise failed 1
  notice: Q: "...ath[curl]} -I -": sh: ${paths.path[curl]}: bad substitution
   error: Method 'http_request_check_status_headers' failed in some repairs
   error: Command related to promiser '${paths.path[curl]}' returned code defined as promise failed 1
  notice: Q: "...ath[curl]} -I -": sh: ${paths.path[curl]}: bad substitution
   error: Method 'http_request_check_status_headers' failed in some repairs

For consistency, and for general ease of use, we should test that curl is available before using it, and preferably fallback on wget if it's available too.