Resolving and then immediately detecting if we have seen the dependency allows us to avoid paying the cost of trying to download and verify the sdist tarball each time that dependency is requested.
On our downstream systems just torch itself was spending 3 minutes total in download_source in a single bootstrap run with all performance features enabled. This brings it down to 5 seconds for torch (didn't measure it for other dependencies)
fixes #510
Resolving and then immediately detecting if we have seen the dependency allows us to avoid paying the cost of trying to download and verify the sdist tarball each time that dependency is requested.
On our downstream systems just torch itself was spending 3 minutes total in
download_sourcein a single bootstrap run with all performance features enabled. This brings it down to 5 seconds for torch (didn't measure it for other dependencies)