uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

pkgs/development/tools/build-managers/fac/default.nix

@@ -0,0 +1,50 @@
+{ lib, stdenv, rustPlatform, fetchCrate, git, CoreServices }:
+
+rustPlatform.buildRustPackage rec {
+  pname = "fac-build";
+  version = "0.5.4";
+
+  src = fetchCrate {
+    inherit version;
+    crateName = "fac";
+    sha256 = "sha256-+JJVuKUdnjJoQJ4a2EE0O6jZdVoFxPwbPgfD2LfiDPI=";
+  };
+
+
+  buildInputs = lib.optionals stdenv.isDarwin [ CoreServices ];
+  cargoSha256 = "sha256-XT4FQVE+buORuZAFZK5Qnf/Fl3QSvw4SHUuCzWhxUdk=";
+
+  # fac includes a unit test called ls_files_works which assumes it's
+  # running in a git repo. Nix's sandbox runs cargo build outside git,
+  # so this test won't work.
+  checkFlagsArray = [ "--skip=ls_files_works" ];
+
+  # fac calls git at runtime, expecting it to be in the PATH,
+  # so we need to patch it to call git by absolute path instead.
+  postPatch = ''
+    substituteInPlace src/git.rs \
+        --replace 'std::process::Command::new("git")' \
+        'std::process::Command::new("${git}/bin/git")'
+  '';
+
+  meta = with lib; {
+    broken = (stdenv.isLinux && stdenv.isAarch64);
+    description = ''
+      A build system that uses ptrace to handle dependencies automatically
+    '';
+    longDescription = ''
+      Fac is a general-purpose build system inspired by make that utilizes
+      ptrace to ensure that all dependences are enumerated and that all
+      source files are added to a (git) repo. An important feature of fac
+      is that it automatically handles dependencies, rather than either
+      complaining about them or giving an incorrect build. Currently, fac
+      only runs on linux systems, but on those systems it is incredibly
+      easy to use!
+    '';
+    homepage = "https://physics.oregonstate.edu/~roundyd/fac";
+    license = licenses.gpl2Plus;
+    platforms = platforms.unix;
+    maintainers = with maintainers; [ dpercy ];
+    mainProgram = "fac";
+  };
+}