README: improve development docs

README.md

@@ -12,7 +12,7 @@ for more details.
 On Linux and macOS the easiest way to Install Nix is to run the following shell command
 (as a user other than root):
 
-```
+```console
 $ curl -L https://nixos.org/nix/install | sh
 ```
 
@@ -20,27 +20,8 @@ Information on additional installation methods is available on the [Nix download
 
 ## Building And Developing
 
-### Building Nix
+See our [Hacking guide](hydra.nixos.org/job/nix/master/build.x86_64-linux/latest/download-by-type/doc/manual#chap-hacking) in our manual for instruction on how to
-
+build nix from source with nix-build or how to get a development environment.
-You can build Nix using one of the targets provided by [release.nix](./release.nix):
-
-```
-$ nix-build ./release.nix -A build.aarch64-linux
-$ nix-build ./release.nix -A build.x86_64-darwin
-$ nix-build ./release.nix -A build.i686-linux
-$ nix-build ./release.nix -A build.x86_64-linux
-```
-
-### Development Environment
-
-You can use the provided `shell.nix` to get a working development environment:
-
-```
-$ nix-shell
-$ ./bootstrap.sh
-$ ./configure
-$ make
-```
 
 ## Additional Resources
 

doc/manual/hacking.xml

@@ -7,15 +7,34 @@
 <para>This section provides some notes on how to hack on Nix. To get
 the latest version of Nix from GitHub:
 <screen>
-$ git clone git://github.com/NixOS/nix.git
+$ git clone https://github.com/NixOS/nix.git
 $ cd nix
 </screen>
 </para>
 
-<para>To build it and its dependencies:
+<para>To build Nix for the current operating system/architecture use</para>
+
 <screen>
-$ nix-build release.nix -A build.x86_64-linux
+$ nix-build
 </screen>
+
+or if you have a flakes-enabled nix:
+
+<screen>
+$ nix build
+</screen>
+
+This will build <literal>defaultPackage</literal> attribute defined in the <literal>flake.nix</literal> file.
+
+To build for other platforms add one of the following suffixes to it: aarch64-linux,
+i686-linux, x86_64-darwin, x86_64-linux.
+
+i.e.
+
+<screen>
+nix-build -A defaultPackage.x86_64-linux
+</screen>
+
 </para>
 
 <para>To build all dependencies and start a shell in which all
@@ -27,13 +46,27 @@ $ nix-shell
 To build Nix itself in this shell:
 <screen>
 [nix-shell]$ ./bootstrap.sh
-[nix-shell]$ configurePhase
+[nix-shell]$ ./configure $configureFlags
-[nix-shell]$ make
+[nix-shell]$ make -j $NIX_BUILD_CORES
 </screen>
 To install it in <literal>$(pwd)/inst</literal> and test it:
 <screen>
 [nix-shell]$ make install
 [nix-shell]$ make installcheck
+[nix-shell]$ ./inst/bin/nix --version
+nix (Nix) 2.4
+</screen>
+
+If you have a flakes-enabled nix you can replace:
+
+<screen>
+$ nix-shell
+</screen>
+
+by:
+
+<screen>
+$ nix develop
 </screen>
 
 </para>