Analyse following RPM build log snippet. Describe contents accurately, without speculation or suggestions for resolution.            
Your analysis must be as concise as possible, while keeping relevant information intact.
Snippet: 
error: Executing url helper "/usr/bin/curl --proto -all,+https,+ftps  --silent --show-error --fail --globoff --location -o /var/lib/copr-rpmbuild/results/run-mozilla.sh https://hg.mozilla.org/mozilla-central/raw-file/tip/build/unix/run-mozilla.sh" failed with status 22
error: Couldn't download https://hg.mozilla.org/mozilla-central/raw-file/tip/build/unix/run-mozilla.sh
During the SRPM creation the helper script (https://hg.mozilla.org/mozilla-central/raw-file/tip/build/unix/run-mozilla.sh) used to create the RPM couldn't be downloaded by curl so execution of the script has failed.