mkDummySrc: allow running a custom script after dummification is done (#116)

CHANGELOG.md

@@ -26,6 +26,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 * `mkCargoDerivation` (along with any of its callers like `cargoBuild`,
   `buildPackage`, etc.) now accept a `stdenv` argument which will override the
   default environment (coming from `pkgs.stdenv`) for that particular derivation
+* `mkDummySrc` now accepts `extraScript` which can be used to run a custom
+  script, and therefore customize what the dummy source contains
+* `buildDepsOnly` now accepts `dummySrc` as a way to directly pass in the dummy
+  source to be used. Automatically derived via `args.src` if not specified.
 
 ## Fixed
 * `cargoAudit` properly keeps any `audit.toml` files when cleaning the source

checks/custom-dummy/.cargo/config.toml

@@ -0,0 +1,2 @@
+[build]
+rustc = "./.cargo/myrustc"

checks/custom-dummy/.cargo/myrustc

@@ -0,0 +1,3 @@
+#!/bin/sh
+echo running custom rustc >&2
+exec rustc "$@"

checks/custom-dummy/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "custom-dummy"
+version = "0.1.0"

checks/custom-dummy/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "custom-dummy"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

checks/custom-dummy/src/main.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}

checks/default.nix

@@ -139,6 +139,14 @@ myPkgs // {
 
   mkDummySrcTests = callPackage ./mkDummySrcTests { };
 
+  # https://github.com/ipetkov/crane/issues/111
+  mkDummySrcCustom = myLib.buildPackage {
+    src = ./custom-dummy;
+    extraDummyScript = ''
+      cp -r ${./custom-dummy/.cargo} -T $out/.cargo
+    '';
+  };
+
   nextest = callPackage ./nextest.nix { };
 
   simple = myLib.buildPackage {

checks/mkDummySrcTests/customized/expected/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "mkDummySrcSimple"
+version = "0.1.0"

checks/mkDummySrcTests/customized/expected/Cargo.toml

@@ -0,0 +1,35 @@
+[[bench]]
+name = "bench1"
+
+[[bench]]
+name = "bench2"
+path = "benches/custom.rs"
+
+[[bin]]
+name = "bin1"
+
+[[bin]]
+name = "bin2"
+path = "src/bin/custom.rs"
+
+[[example]]
+name = "example1"
+
+[[example]]
+name = "example2"
+path = "examples/custom.rs"
+
+[[test]]
+name = "test1"
+
+[[test]]
+name = "test2"
+path = "tests/custom.rs"
+
+[lib]
+name = "foo"
+
+[package]
+edition = "2021"
+name = "mkDummySrcSimple"
+version = "0.1.0"

checks/mkDummySrcTests/customized/expected/another-custom-file.txt

@@ -0,0 +1 @@
+another additional file

checks/mkDummySrcTests/customized/expected/benches/bench1.rs

@@ -0,0 +1,2 @@
+#![allow(dead_code)]
+pub fn main() {}

checks/mkDummySrcTests/customized/expected/benches/custom.rs

@@ -0,0 +1,2 @@
+#![allow(dead_code)]
+pub fn main() {}

checks/mkDummySrcTests/customized/expected/build.rs

@@ -0,0 +1,2 @@
+#![allow(dead_code)]
+pub fn main() {}

checks/mkDummySrcTests/customized/expected/examples/custom.rs

@@ -0,0 +1,2 @@
+#![allow(dead_code)]
+pub fn main() {}

checks/mkDummySrcTests/customized/expected/examples/example1.rs

@@ -0,0 +1,2 @@
+#![allow(dead_code)]
+pub fn main() {}

checks/mkDummySrcTests/customized/expected/extra-custom-file.txt

@@ -0,0 +1 @@
+some additional file

checks/mkDummySrcTests/customized/expected/src/bin/bin1.rs

@@ -0,0 +1,2 @@
+#![allow(dead_code)]
+pub fn main() {}

checks/mkDummySrcTests/customized/expected/src/bin/custom.rs

@@ -0,0 +1,2 @@
+#![allow(dead_code)]
+pub fn main() {}

checks/mkDummySrcTests/customized/expected/src/lib.rs

@@ -0,0 +1,2 @@
+#![allow(dead_code)]
+pub fn main() {}

checks/mkDummySrcTests/customized/expected/tests/custom.rs

@@ -0,0 +1,2 @@
+#![allow(dead_code)]
+pub fn main() {}

checks/mkDummySrcTests/customized/expected/tests/test1.rs

@@ -0,0 +1,2 @@
+#![allow(dead_code)]
+pub fn main() {}

checks/mkDummySrcTests/customized/input/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "mkDummySrcSimple"
+version = "0.1.0"

checks/mkDummySrcTests/customized/input/Cargo.toml

@@ -0,0 +1,35 @@
+[package]
+name = "mkDummySrcSimple"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+name = "foo"
+
+[[bin]]
+name = "bin1"
+
+[[bin]]
+name = "bin2"
+path = "src/bin/custom.rs"
+
+[[example]]
+name = "example1"
+
+[[example]]
+name = "example2"
+path = "examples/custom.rs"
+
+[[test]]
+name = "test1"
+
+[[test]]
+name = "test2"
+path = "tests/custom.rs"
+
+[[bench]]
+name = "bench1"
+
+[[bench]]
+name = "bench2"
+path = "benches/custom.rs"

checks/mkDummySrcTests/customized/input/extra-custom-file.txt

@@ -0,0 +1 @@
+some additional file

checks/mkDummySrcTests/customized/input/src/lib.rs

@@ -0,0 +1,4 @@
+fn main() {
+    println!("Hello, world!");
+}
+

checks/mkDummySrcTests/default.nix

@@ -5,17 +5,21 @@
 }:
 
 let
-  cmpDummySrcRaw = name: input: expected:
+  doCompare = name: expected: actual:
+    runCommand "compare-${name}" { } ''
+      echo ${expected} ${actual}
+      diff -r ${expected} ${actual}
+      touch $out
+    '';
+
+
+  cmpDummySrcRaw = name: expected: input:
     let
       dummySrc = mkDummySrc {
         src = input;
       };
     in
-    runCommand "compare-${name}" { } ''
-      echo ${expected} ${dummySrc}
-      diff -r ${expected} ${dummySrc}
-      touch $out
-    '';
+    doCompare name expected dummySrc;
 
   cmpDummySrc = name: path:
     let
@@ -35,12 +39,27 @@ let
       };
     in
     [
-      (cmpDummySrcRaw name input expected)
-      (cmpDummySrcRaw "${name}-filtered" filteredInput expected)
+      (cmpDummySrcRaw name expected input)
+      (cmpDummySrcRaw "${name}-filtered" expected filteredInput)
     ];
+
+  customizedDummy =
+    let
+      expected = ./customized/expected;
+      input = ./customized/input;
+    in
+    doCompare "customized" expected (mkDummySrc {
+      src = input;
+      extraDummyScript = ''
+        cp ${input}/extra-custom-file.txt $out
+        echo 'another additional file' >$out/another-custom-file.txt
+      '';
+    });
 in
 linkFarmFromDrvs "cleanCargoToml" (lib.flatten [
   (cmpDummySrc "single" ./single)
   (cmpDummySrc "single-alt" ./single-alt)
   (cmpDummySrc "workspace" ./workspace)
+
+  customizedDummy
 ])

docs/API.md

@@ -114,6 +114,9 @@ to influence its behavior.
   - Default value: `"${cargoTestCommand} ${cargoExtraArgs}"`
 * `doCheck`: whether the derivation's check phase should be run
   - Default value: `true`
+* `dummySrc`: the "dummy" source to use when building this derivation.
+  Automatically derived if not passed in
+  - Default value: `mkDummySrc args.src`
 * `pname`: package name of the derivation
   - Default value: inherited from calling `crateNameFromCargoToml`
 * `version`: version of the derivation
@@ -129,6 +132,7 @@ environment variables during the build, you can bring them back via
 * `cargoCheckCommand`
 * `cargoExtraArgs`
 * `cargoTestCommand`
+* `dummySrc`
 
 ### `lib.buildPackage`
 
@@ -794,6 +798,41 @@ build caches. More specifically:
 #### Optional attributes
 * `cargoLock`: a path to a Cargo.lock file
   - Default value: `src + /Cargo.lock`
+* `extraDummyScript`: additional shell script which will be run inside the builder
+  verbatim. Useful for customizing what the dummy sources include by running any
+  arbitrary commands.
+  - Default value: `""`
+  - Note that this script will run in an environment
+    _where the original source is not present_ as doing so would cause a rebuild
+    if any part of the source changed. Additional files can be copied to the
+    derivation's result, but care must be taken that the derivation only depends
+    on (i.e. is rebuilt if) the smallest subset of the original source as
+    required.
+  - Here is an example of how to include an entire directory, in this case
+    `.cargo`, but any other directory would work as well:
+    ```nix
+    let
+    in
+    mkDummySrc {
+      # The _entire_ source of the project. mkDummySrc will automatically
+      # filter out irrelevant files as described above
+      src = ./.;
+
+      # Note that here we scope the path to just `./.cargo` and not any other
+      # directories which may exist at the root of the project. Also note that
+      # the entire path is inside of the `${ }` which ensures that the
+      # derivation only consumes that directory. Writing `${./.}/.cargo` would
+      # incorectly consume the entire source root, and therefore rebuild
+      # everything when any file changes, which defeats artifact caching.
+      #
+      # Also note the `--no-target-directory` flag which ensures the results are
+      # copied to `$out/.cargo` instead of something like `$out/HASH-.cargo`
+      extraDummyScript = ''
+        cp -r ${./.cargo} --no-target-directory $out/.cargo
+      '';
+    }
+    ```
+
 
 ### `lib.overrideToolchain`
 

lib/buildDepsOnly.nix

@@ -17,6 +17,7 @@ let
     "cargoCheckCommand"
     "cargoExtraArgs"
     "cargoTestCommand"
+    "dummySrc"
   ];
 
   throwMsg = throw ''
@@ -28,10 +29,10 @@ let
 
   path = args.src or throwMsg;
   cargoToml = path + "/Cargo.toml";
-  dummySrc =
-    if builtins.pathExists cargoToml
+  dummySrc = args.dummySrc or
+    (if builtins.pathExists cargoToml
     then mkDummySrc args
-    else throwMsg;
+    else throwMsg);
 in
 mkCargoDerivation (cleanedArgs // {
   src = dummySrc;

lib/mkDummySrc.nix

@@ -8,6 +8,7 @@
 
 { src
 , cargoLock ? null
+, extraDummyScript ? ""
 , ...
 }:
 let
@@ -187,4 +188,5 @@ runCommandLocal "dummy-src" { } ''
   cp --recursive --no-preserve=mode,ownership ${cleanSrc}/. -t $out
   ${copyCargoLock}
   ${copyAndStubCargoTomls}
+  ${extraDummyScript}
 ''