this appears to occur even with builders-use-substitutes=true
Is this based on code you read or behaviour you observed?
tazjin at 2020-08-01T14·03+00
grfn at 2020-08-01T15·04+00
understand what's going on here a little better now - it looks like builtin fetchers such as
fetchTarballactually execute on the client, then upload their results to the daemon via
AddToStoreNar- I can only imagine storing the result in memory along the way (ugh). What this really should be is a method in the store protocol to execute a fetcher on the target.
grfn at 2020-08-06T03·01+00
More interesting stuff here that I'm observing in upstream nix - if the path for a goal already exists on the remote builder but that remote builder is not configured as a substituter, the build will download that path from the remote builder, even though it's only necessary at the location where we're building the derivation
grfn at 2020-08-21T13·44+00