Documentation update. [ci skip]

(cherry picked from commit b8b3b414)

Cabal/doc/nix-local-build.rst

@@ -178,7 +178,7 @@ version of cabal-install:
    executable or test suite named ``pexe``, it would be located at
    ``dist-newstyle/build/p-0.1/build/pexe/pexe``.
 
--  In cabal-install-2.0 and above, the dist directory for a package ``p-0.1``
+-  In cabal-install-2.0, the dist directory for a package ``p-0.1``
    defining a library built with GHC 8.0.1 on 64-bit Linux is
    ``dist-newstyle/build/x86_64-linux/ghc-8.0.1/p-0.1``. When
    per-component builds are enabled (any non-Custom package), a
@@ -189,6 +189,17 @@ version of cabal-install:
    ``dist-newstyle/build/x86_64-linux/ghc-8.0.1/p-0.1/c/pexe/build/pexe/pexe``
    (you can see why we want this to be an implementation detail!)
 
+- In cabal-install-2.2 and above, the ``/c/`` part of the above path
+   is replaced with one of ``/l/``, ``/x/``, ``/f/``, ``/t/``, or
+   ``/b/``, depending on the type of component (sublibrary,
+   executable, foreign library, test suite, or benchmark
+   respectively). So the full path to an executable named ``pexe``
+   compiled with GHC 8.0.1 on a 64-bit Linux is now
+   ``dist-newstyle/build/x86_64-linux/ghc-8.0.1/p-0.1/x/pexe/build/pexe/pexe``;
+   for a benchmark named ``pbench`` it now is
+   ``dist-newstyle/build/x86_64-linux/ghc-8.0.1/p-0.1/b/pbench/build/pbench/pbench``;
+
+
 The paths are a bit longer in 2.0 and above but the benefit is that you can
 transparently have multiple builds with different versions of GHC. We
 plan to add the ability to create aliases for certain build