Non broken fetchcargo

pkgs/applications/misc/alacritty/default.nix

@@ -1,6 +1,6 @@
 { stdenv,
   lib,
-  fetchgit,
+  fetchFromGitHub,
   rustPlatform,
   cmake,
   makeWrapper,
@@ -51,18 +51,16 @@ let
   ];
 in buildRustPackage rec {
   name = "alacritty-unstable-${version}";
-  version = "2018-08-30";
-
-  # At the moment we cannot handle git dependencies in buildRustPackage.
-  # This fork only replaces rust-fontconfig/libfontconfig with a git submodules.
-  src = fetchgit {
-    url = https://github.com/Mic92/alacritty.git;
-    rev = "rev-${version}";
-    sha256 = "0izvg7dwwb763jc6gnmn47i5zrkxvmh3vssn6vzrrmqhd4j3msmf";
-    fetchSubmodules = true;
+  version = "2018-08-05";
+
+  src = fetchFromGitHub {
+    owner = "jwilm";
+    repo = "alacritty";
+    rev = "1adb5cb7fc05054197aa08e0d1fa957df94888ab";
+    sha256 = "06rc7dy1vn59lc5hjh953h9lh0f39c0n0jmrz472mrya722fl2ab";
   };
 
-  cargoSha256 = "1ijgkwv9ij4haig1h6n2b9xbhp5vahy9vp1sx72wxaaj9476msjx";
+  cargoSha256 = "0ms0248bb2lgbzcqks6i0qhn1gaiim3jf1kl17qw52c8an3rc652";
 
   nativeBuildInputs = [
     cmake

pkgs/build-support/rust/cargo-vendor-normalise.py

@@ -0,0 +1,41 @@
+#!/usr/bin/env python
+
+import sys
+
+import toml
+
+
+def quote(s: str) -> str:
+    escaped = s.replace('"', r"\"").replace("\n", r"\n").replace("\\", "\\\\")
+    return '"{}"'.format(escaped)
+
+
+def main() -> None:
+    data = toml.load(sys.stdin)
+
+    assert list(data.keys()) == ["source"]
+
+    # this value is non deterministic
+    data["source"]["vendored-sources"]["directory"] = "@vendor@"
+
+    lines = []
+    inner = data["source"]
+    for source, attrs in sorted(inner.items()):
+        lines.append("[source.{}]".format(quote(source)))
+        if source == "vendored-sources":
+            lines.append('"directory" = "@vendor@"\n')
+        else:
+            for key, value in sorted(attrs.items()):
+                attr = "{} = {}".format(quote(key), quote(value))
+                lines.append(attr)
+        lines.append("")
+
+    result = "\n".join(lines)
+    real = toml.loads(result)
+    assert real == data, "output = {} while input = {}".format(real, data)
+
+    print(result)
+
+
+if __name__ == "__main__":
+    main()

pkgs/build-support/rust/default.nix

@@ -1,7 +1,7 @@
-{ stdenv, cacert, git, rust, cargo-vendor }:
+{ stdenv, cacert, git, rust, cargo-vendor, python3 }:
 let
   fetchcargo = import ./fetchcargo.nix {
-    inherit stdenv cacert git rust cargo-vendor;
+    inherit stdenv cacert git rust cargo-vendor python3;
   };
 in
 { name, cargoSha256 ? "unset"
@@ -61,14 +61,12 @@ in stdenv.mkDerivation (args // {
     ${setupVendorDir}
 
     mkdir .cargo
-    cat >.cargo/config <<-EOF
-      [source.crates-io]
-      registry = 'https://github.com/rust-lang/crates.io-index'
-      replace-with = 'vendored-sources'
-
-      [source.vendored-sources]
-      directory = '$(pwd)/$cargoDepsCopy'
-    EOF
+    config="$(pwd)/$cargoDepsCopy/.cargo/config";
+    if [[ ! -e $config ]]; then
+      config=${./fetchcargo-default-config.toml};
+    fi;
+    substitute $config .cargo/config \
+    --subst-var-by vendor "$(pwd)/$cargoDepsCopy"
 
     unset cargoDepsCopy
 

pkgs/build-support/rust/fetchcargo-default-config.toml

@@ -0,0 +1,7 @@
+[source."crates-io"]
+"replace-with" = "vendored-sources"
+
+[source."vendored-sources"]
+"directory" = "@vendor@"
+
+

pkgs/build-support/rust/fetchcargo.nix

@@ -1,8 +1,26 @@
-{ stdenv, cacert, git, rust, cargo-vendor }:
+{ stdenv, cacert, git, rust, cargo-vendor, python3 }:
+let cargo-vendor-normalise = stdenv.mkDerivation {
+  name = "cargo-vendor-normalise";
+  src = ./cargo-vendor-normalise.py;
+  nativeBuildInputs = [ python3.pkgs.wrapPython ];
+  unpackPhase = ":";
+  installPhase = "install -D $src $out/bin/cargo-vendor-normalise";
+  pythonPath = [ python3.pkgs.toml ];
+  postFixup = "wrapPythonPrograms";
+  doInstallCheck = true;
+  installCheckPhase = ''
+    # check that ./fetchcargo-default-config.toml is a fix point
+    reference=${./fetchcargo-default-config.toml}
+    < $reference $out/bin/cargo-vendor-normalise > test;
+    cmp test $reference
+  '';
+  preferLocalBuild = true;
+};
+in
 { name ? "cargo-deps", src, srcs, patches, sourceRoot, sha256, cargoUpdateHook ? "" }:
 stdenv.mkDerivation {
   name = "${name}-vendor";
-  nativeBuildInputs = [ cacert cargo-vendor git rust.cargo ];
+  nativeBuildInputs = [ cacert cargo-vendor git cargo-vendor-normalise rust.cargo ];
   inherit src srcs patches sourceRoot;
 
   phases = "unpackPhase patchPhase installPhase";
@@ -23,9 +41,16 @@ stdenv.mkDerivation {
 
     ${cargoUpdateHook}
 
-    cargo vendor
-
-    cp -ar vendor $out
+    mkdir -p $out
+    cargo vendor $out | cargo-vendor-normalise > config
+    # fetchcargo used to never keep the config output by cargo vendor
+    # and instead hardcode the config in ./fetchcargo-default-config.toml.
+    # This broke on packages needing git dependencies, so now we keep the config.
+    # But not to break old cargoSha256, if the previous behavior was enough,
+    # we don't store the config.
+    if ! cmp config ${./fetchcargo-default-config.toml} > /dev/null; then
+      install -Dt $out/.cargo config;
+    fi;
   '';
 
   outputHashAlgo = "sha256";