Commit graph

30 commits

Author SHA1 Message Date
Martin Schwaighofer 9504445cab git fetcher: distinguish errors more precisely 2022-02-19 22:58:23 +01:00
Martin Schwaighofer c7e527b82b git fetcher: invoke diff instead of diff-index
diff-index operates on the view that git has of the working tree,
which might be outdated. The higher-level diff command does this
automatically. This change also adds handling for submodules.

fixes #4140

Alternative fixes would be invoking update-index before diff-index or
matching more closely what require_clean_work_tree from git-sh-setup.sh
does, but both those options make it more difficult to reason about
correctness.
2022-02-19 22:58:23 +01:00
Martin Schwaighofer 0bfa0cdea1 git fetcher: improve check for valid repository
The .git/refs/heads directory might be empty for a valid
usable git repository. This often happens in CI environments,
which might only fetch commits, not branches.
Therefore instead we let git itself check if HEAD points to
something that looks like a commit.

fixes #5302
2022-02-19 22:58:22 +01:00
regnat 83615fcf8f Allow fetchGit to take a name argument
Fix #3388
2021-07-06 08:41:52 +02:00
Bjørn Forsman f2a799b16d tests: check that builtins.fetchGit { ..., ref = "HEAD"; } works 2021-03-30 11:39:37 +02:00
Maximilian Bosch 897ae235fc
tests/fetchGit: test behavior of allRefs = true; 2020-12-22 12:18:10 +01:00
Eelco Dolstra 05d9442f68 builtins.fetchGit: Fix shortRev attribute for dirty trees 2020-11-26 21:45:28 +01:00
Maximilian Bosch e4940e90f3
Restore backwards-compat for current builtins.fetchGit
If a repo is dirty, it used to return a `rev` object with an "empty"
sha1 (0000000000000000000000000000000000000000). Please note that this
only applies for `builtins.fetchGit` and *not* for `builtins.fetchTree{
type = "git"; }`.
2020-07-28 22:46:39 +02:00
Maximilian Bosch f742438465
Merge legacy fetchGit-builtin with the generic fetchTree-function
The original idea was to implement a git-fetcher in Nix's core that
supports content hashes[1]. In #3549[2] it has been suggested to
actually use `fetchTree` for this since it's a fairly generic wrapper
over the new fetcher-API[3] and already supports content-hashes.

This patch implements a new git-fetcher based on `fetchTree` by
incorporating the following changes:

* Removed the original `fetchGit`-implementation and replaced it with an
  alias on the `fetchTree` implementation.

* Ensured that the `git`-fetcher from `libfetchers` always computes a
  content-hash and returns an "empty" revision on dirty trees (the
  latter one is needed to retain backwards-compatibility).

* The hash-mismatch error in the fetcher-API exits with code 102 as it
  usually happens whenever a hash-mismatch is detected by Nix.

* Removed the `flakes`-feature-flag: I didn't see a reason why this API
  is so tightly coupled to the flakes-API and at least `fetchGit` should
  remain usable without any feature-flags.

* It's only possible to specify a `narHash` for a `git`-tree if either a
  `ref` or a `rev` is given[4].

* It's now possible to specify an URL without a protocol. If it's missing,
  `file://` is automatically added as it was the case in the original
  `fetchGit`-implementation.

[1] https://github.com/NixOS/nix/pull/3216
[2] https://github.com/NixOS/nix/pull/3549#issuecomment-625194383
[3] https://github.com/NixOS/nix/pull/3459
[4] https://github.com/NixOS/nix/pull/3216#issuecomment-553956703
2020-07-28 00:44:39 +02:00
Eelco Dolstra 38e360154d
Git: Use unified caching system 2020-03-17 22:35:29 +01:00
Eelco Dolstra d1165d8791
Require shallow clones to be requested explicitly
If you do a fetchTree on a Git repository, whether the result contains
a revCount attribute should not depend on whether that repository
happens to be a shallow clone or not. That would complicate caching a
lot and would be semantically messy. So applying fetchTree/fetchGit to
a shallow repository is now an error unless you pass the attribute
'shallow = true'. If 'shallow = true', we don't return revCount, even
if the repository is not actually shallow.

Note that Nix itself is not doing shallow clones at the moment. But it
could do so as an optimisation if the user specifies 'shallow = true'.

Issue #2988.
2020-03-17 22:35:29 +01:00
Eelco Dolstra fbcb897e21
Add a test for shallow Git clones
Also, don't return a revCount anymore for shallow or dirty Git trees,
since it's incorrect.

Closes #2988.
2020-03-16 13:20:32 +01:00
Eelco Dolstra 34c7645a58
Fix re-running the fetchGit.sh test 2020-03-16 12:30:11 +01:00
Maximilian Bosch c169ea5904
builtins.fetchGit: Fix build when fetching a git worktree
Worktrees[1] are a feature of git which allow you to check out a ref in
a different directory.

While playing around with flakes I realized that git repositories in a
worktree checkout break when trying to build a flake:

```
$ git worktree add ../nixpkgs-flakes nixpkgs-flakes
$ cd ../nixpkgs-flakes
$ nix build .#hello
error: opening directory '/home/ma27/Projects/nixpkgs-flakes/.git/refs/heads': Not a directory
```

This issue has been fixed by determining with `git rev-parse --git-common-dir`
where the actual `.git` directory is.

Please note that this issue only exists on the `flakes` branch, fetching
worktree checkouts with Nix master seems to work fine.

[1] https://git-scm.com/docs/git-worktree
2020-02-19 14:00:36 +01:00
Eelco Dolstra 9f4d8c6170 Pluggable fetchers
Flakes are now fetched using an extensible mechanism. Also lots of
other flake cleanups.
2020-01-21 22:56:04 +01:00
Eelco Dolstra ca8caaec5e nix: Add --expr flag
This replaces the '(...)' installable syntax, which is not very
discoverable. The downside is that you can't have multiple expressions
or mix expressions and other installables.
2019-11-27 00:05:30 +01:00
Eelco Dolstra a56036fa87 Fix repeated fetchGit.sh test 2019-10-16 00:21:19 +02:00
Eelco Dolstra 638c56caed
Remove outdated fetchGit test
It's no longer an error if we can't update our clone.
2019-05-26 15:59:50 +02:00
Eelco Dolstra 0cbda84f5b exportGit: Don't clone local repositories
This ensures that commands like 'nix flake info /my/nixpkgs' don't
copy a gigabyte of crap to ~/.cache/nix.

Fixes #60.
2019-04-19 14:10:57 +02:00
Eelco Dolstra ee1254d4f5 nix: Add --impure as a shorter alias of --no-pure-eval 2019-04-08 23:19:19 +02:00
Eelco Dolstra d2875f6782 Fix tests 2019-04-08 16:11:36 +02:00
Graham Christensen 02098d2073 fetchGit: use a better caching scheme
The current usage technically works by putting multiple different
repos in to the same git directory. However, it is very slow as
Git tries very hard to find common commits between the two
repositories. If the two repositories are large (like Nixpkgs and
another long-running project,) it is maddeningly slow.

This change busts the cache for existing deployments, but users
will be promptly repaid in per-repository performance.
2018-08-17 11:27:34 -04:00
Eelco Dolstra d4dcffd643
Add pure evaluation mode
In this mode, the following restrictions apply:

* The builtins currentTime, currentSystem and storePath throw an
  error.

* $NIX_PATH and -I are ignored.

* fetchGit and fetchMercurial require a revision hash.

* fetchurl and fetchTarball require a sha256 attribute.

* No file system access is allowed outside of the paths returned by
  fetch{Git,Mercurial,url,Tarball}. Thus 'nix build -f ./foo.nix' is
  not allowed.

Thus, the evaluation result is completely reproducible from the
command line arguments. E.g.

  nix build --pure-eval '(
    let
      nix = fetchGit { url = https://github.com/NixOS/nixpkgs.git; rev = "9c927de4b179a6dd210dd88d34bda8af4b575680"; };
      nixpkgs = fetchGit { url = https://github.com/NixOS/nixpkgs.git; ref = "release-17.09"; rev = "66b4de79e3841530e6d9c6baf98702aa1f7124e4"; };
    in (import (nix + "/release.nix") { inherit nix nixpkgs; }).build.x86_64-linux
  )'

The goal is to enable completely reproducible and traceable
evaluation. For example, a NixOS configuration could be fully
described by a single Git commit hash. 'nixos-rebuild' would do
something like

  nix build --pure-eval '(
    (import (fetchGit { url = file:///my-nixos-config; rev = "..."; })).system
  ')

where the Git repository /my-nixos-config would use further fetchGit
calls or Git externals to fetch Nixpkgs and whatever other
dependencies it has. Either way, the commit hash would uniquely
identify the NixOS configuration and allow it to reproduced.
2018-01-16 19:23:18 +01:00
Will Dietz 84d9e213d2 fetchGit.sh: Test we don't "corrupt" cache if invoke w/o git avail 2018-01-09 08:58:19 -06:00
Will Dietz 2e6f06c37e fetchGit: Fix handling of local repo when not using 'master' branch
Add tests checking this behavior.
2017-12-22 15:29:52 -06:00
Shea Levy eedbc4e06c
fetchGit: Ignore tarballTtl if rev is set and not in the repo.
Fixes #1697.
2017-11-24 06:09:24 -05:00
Eelco Dolstra d7da6c9ea9
fetchGit/fetchMercurial: Fix directory inclusion check
E.g. the existence of .gitignore would cause .git to be included.
2017-11-21 19:34:46 +01:00
Eelco Dolstra fd10f6f241
Show when tests are skipped
Also, don't depend on tput (ncurses). It's really not needed since
ANSI escape sequences have been standardized for 35 years or so.
2017-11-07 12:09:57 +01:00
Eelco Dolstra ee6ac38848
fetchGit/fetchMercurial: Filter out directories with untracked files 2017-11-03 13:55:31 +01:00
Eelco Dolstra 4dee01da7c
fetchGit: Add a test 2017-11-03 13:55:30 +01:00