fetchTarball, fetchTree, and fetchGit all have *optional* hash attrs.
This means that we need to be careful with what we allow to avoid
accidentally making these defaults. When ‘hash = ""’ we assume the
empty hash is wanted.
As `git fetch` may chose to interpret refspec to it's liking, ensure that we
only pass refs that begin with `refs/` as is, otherwise, prepend them with
`refs/heads`. Otherwise, branches named `heads/foo` (I know it's bad, but it's
allowed), would be fetched as `foo`, instead of `heads/foo`.
The previous regex was too strict and did not match what git was allowing. It
could lead to `fetchGit` not accepting valid branch names, even though they
exist in a repository (for example, branch names containing `/`, which are
pretty standard, like `release/1.0` branches).
The new regex defines what a branch name should **NOT** contain. It takes the
definitions from `refs.c` in https://github.com/git/git and `git help
check-ref-format` pages.
This change also introduces a test for ref name validity checking, which
compares the result from Nix with the result of `git check-ref-format --branch`.
The attributes previously stored in TreeInfo (narHash, revCount,
lastModified) are now stored in Input. This makes it less arbitrary
what attributes are stored where.
As a result, the lock file format has changed. An entry like
"info": {
"lastModified": 1585405475,
"narHash": "sha256-bESW0n4KgPmZ0luxvwJ+UyATrC6iIltVCsGdLiphVeE="
},
"locked": {
"owner": "NixOS",
"repo": "nixpkgs",
"rev": "b88ff468e9850410070d4e0ccd68c7011f15b2be",
"type": "github"
},
is now stored as
"locked": {
"owner": "NixOS",
"repo": "nixpkgs",
"rev": "b88ff468e9850410070d4e0ccd68c7011f15b2be",
"type": "github",
"lastModified": 1585405475,
"narHash": "sha256-bESW0n4KgPmZ0luxvwJ+UyATrC6iIltVCsGdLiphVeE="
},
The 'Input' class is now a dumb set of attributes. All the fetcher
implementations subclass InputScheme, not Input. This simplifies the
API.
Also, fix substitution of flake inputs. This was broken since lazy
flake fetching started using fetchTree internally.
The idea is it's always more flexible to consumer a `Source` than a
plain string, and it might even reduce memory consumption.
I also looked at `addToStoreFromDump` with its `// FIXME: remove?`, but
the worked needed for that is far more up for interpretation, so I
punted for now.
In particular, doing 'nix build /path/to/dir' now works if
/path/to/dir is not a Git tree (it only has to contain a flake.nix
file).
Also, 'nix flake init' no longer requires a Git tree (but it will do a
'git add flake.nix' if it's a Git tree)
This fetchers copies a plain directory (i.e. not a Git/Mercurial
repository) to the store (or does nothing if the path is already a
store path).
One use case is to pin the 'nixpkgs' flake used to build the current
NixOS system, and prevent it from being garbage-collected, via a
system registry entry like this:
{
"from": {
"id": "nixpkgs",
"type": "indirect"
},
"to": {
"type": "path",
"path": "/nix/store/rralhl3wj4rdwzjn16g7d93mibvlr521-source",
"lastModified": 1585388205,
"rev": "b0c285807d6a9f1b7562ec417c24fa1a30ecc31a"
},
"exact": true
}
Note the fake "lastModified" and "rev" attributes that ensure that the
flake gives the same evaluation results as the corresponding
Git/GitHub inputs.
(cherry picked from commit 12f9379123)
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 (c169ea5904).
This fetchers copies a plain directory (i.e. not a Git/Mercurial
repository) to the store (or does nothing if the path is already a
store path).
One use case is to pin the 'nixpkgs' flake used to build the current
NixOS system, and prevent it from being garbage-collected, via a
system registry entry like this:
{
"from": {
"id": "nixpkgs",
"type": "indirect"
},
"to": {
"type": "path",
"path": "/nix/store/rralhl3wj4rdwzjn16g7d93mibvlr521-source",
"lastModified": 1585388205,
"rev": "b0c285807d6a9f1b7562ec417c24fa1a30ecc31a"
},
"exact": true
}
Note the fake "lastModified" and "rev" attributes that ensure that the
flake gives the same evaluation results as the corresponding
Git/GitHub inputs.
An example use is for pinning the "nixpkgs" entry the system-wide
registry to a particular store path. Inexact matches
(e.g. "nixpkgs/master") should still use the global registry.
One application for this is pinning the 'nixpkgs' flake to the exact
revision used to build the NixOS system, e.g.
{
"flakes": [
{
"from": {
"id": "nixpkgs",
"type": "indirect"
},
"to": {
"owner": "NixOS",
"repo": "nixpkgs",
"type": "github",
"rev": "b0c285807d6a9f1b7562ec417c24fa1a30ecc31a"
}
}
],
"version": 2
}
