Backport libfetchers from the flakes branch

This provides a pluggable mechanism for defining new fetchers. It adds
a builtin function 'fetchTree' that generalizes existing fetchers like
'fetchGit', 'fetchMercurial' and 'fetchTarball'. 'fetchTree' takes a
set of attributes, e.g.

  fetchTree {
    type = "git";
    url = "https://example.org/repo.git";
    ref = "some-branch";
    rev = "abcdef...";
  }

The existing fetchers are just wrappers around this. Note that the
input attributes to fetchTree are the same as flake input
specifications and flake lock file entries.

All fetchers share a common cache stored in
~/.cache/nix/fetcher-cache-v1.sqlite. This replaces the ad hoc caching
mechanisms in fetchGit and download.cc (e.g. ~/.cache/nix/{tarballs,git-revs*}).

This also adds support for Git worktrees (c169ea59049f861aaba429f48b828d0820b74d1d).

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libstore/derivations.cc b/src/libstore/derivations.cc
index 973ddc86a..0067032af 100644
--- a/src/libstore/derivations.cc
+++ b/src/libstore/derivations.cc
@@ -378,7 +378,7 @@ Hash hashDerivationModulo(Store & store, const Derivation & drv, bool maskOutput
         if (h == drvHashes.end()) {
             assert(store.isValidPath(i.first));
             h = drvHashes.insert_or_assign(i.first.clone(), hashDerivationModulo(store,
-                readDerivation(store, store.toRealPath(store.printStorePath(i.first))), false)).first;
+                readDerivation(store, store.toRealPath(i.first)), false)).first;
         }
         inputs2.insert_or_assign(h->second.to_string(Base16, false), i.second);
     }