WIP: fetchTree: substitute from binary caches before trying to fetch #4149
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This allows fetching the referred sources from a binary cache in
addition to the original source Uri. In cases where accessing the
upstream is expensive, slow or unreliable and the soures are within on
of the trusted binary caches we can now subsitute them from there.
TODOs:
- [ ] mostly a copy of what substitution-goal.cc does
- [ ] figure out which of the headers clangd pulled in on the fly are
actually required for this
- [ ] what are the downsides of having getPublicKeys public? It
appears that at least one of the friend class cases only existed
because it was not public.
Relates to NixOS#2114
Check out #3754, which among many other changes does this without copying that stuff. |
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In fact nix/src/libfetchers/fetchers.cc Line 122 in 11882d7 |
The reason might be that I'm using a release version of Nix (2.3.7) and didn't expect this to have been changed. |
That indeed looks much nicer! Looking forward to play with that once it's merged/released 👍 |
This allows fetching the referred sources from a binary cache in
addition to the original source Uri. In cases where accessing the
upstream is expensive, slow or unreliable and the soures are within on
of the trusted binary caches we can now subsitute them from there.
TODOs:
actually required for this
appears that at least one of the friend class cases only existed
because it was not public.
Relates to #2114