mkCargoDerivation: populate pname and version if not specified

CHANGELOG.md

@@ -12,6 +12,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
   reference to a (possibly different) executable in the store.
 * `mkCargoDerivation` now automatically vendors dependencies if `cargoVendorDir`
   is not defined
+* `mkCargoDerivation` now automatically populates `pname` and `version` (via
+  `crateNameFromCargoToml`) if they are not specified
 
 ### Fixed
 * Installing binaries now uses the same version of cargo as was used to build

docs/API.md

@@ -712,7 +712,6 @@ This is a fairly low-level abstraction, so consider using `buildPackage` or
 * `checkPhaseCargoCommand`: A command (likely a cargo invocation) to run during
   the derivation's check phase. Pre and post check hooks will automatically be
   run.
-* `pname`: the package name used for the derivation
 
 #### Optional attributes
 * `buildPhase`: the commands used by the build phase of the derivation
@@ -742,10 +741,14 @@ This is a fairly low-level abstraction, so consider using `buildPackage` or
   - By default an output directory is created such that any other `postInstall`
     hooks can successfully run. Consider overriding this value with an
     appropriate installation commands for the package being built.
+* `pname`: the name of the derivation
+  - Default value: the package name listed in `Cargo.toml`
 * `pnameSuffix`: a suffix appended to `pname`
   - Default value: `""`
 * `stdenv`: the standard build environment to use for this derivation
   - Default value: `pkgs.stdenv`
+* `version`: the version of the derivation
+  - Default value: the version listed in `Cargo.toml`
 
 #### Remove attributes
 The following attributes will be removed before being lowered to

lib/mkCargoDerivation.nix

@@ -2,6 +2,7 @@
 , cargoHelperFunctionsHook
 , configureCargoCommonVarsHook
 , configureCargoVendoredDepsHook
+, crateNameFromCargoToml
 , inheritCargoArtifactsHook
 , installCargoArtifactsHook
 , lib
@@ -26,6 +27,7 @@ args@{
 , ...
 }:
 let
+  crateName = crateNameFromCargoToml args;
   chosenStdenv = args.stdenv or stdenv;
   cleanedArgs = builtins.removeAttrs args [
     "buildPhaseCargoCommand"
@@ -36,7 +38,8 @@ let
   ];
 in
 chosenStdenv.mkDerivation (cleanedArgs // {
-  pname = "${args.pname}${args.pnameSuffix or ""}";
+  pname = "${args.pname or crateName.pname}${args.pnameSuffix or ""}";
+  version = args.version or crateName.version;
 
   # Controls whether cargo's `target` directory should be copied as an output
   doInstallCargoArtifacts = args.doInstallCargoArtifacts or true;