doc: suggest GNULIB_REFDIR instead of GNULIB_SRCDIR

* README-hacking: Use GNULIB_REFDIR instead of GNULIB_SRCDIR since that
is the correct way to have ./bootstrap do 'git clone --reference'.

diff --git a/README-hacking b/README-hacking
index 17e548edcaf7a77e11c9fa24df85bd966c010a30..c6529ac2c1a29ef34b26688763f952b3d45729c3 100644 (file)
--- a/README-hacking
+++ b/README-hacking
@@ -43,7 +43,7 @@ As an optional step, if you already have a copy of the Gnulib Git
 repository, then you can use it as a reference to reduce download
 time and file system space requirements:
 
-        $ export GNULIB_SRCDIR=/path/to/gnulib
+        $ export GNULIB_REFDIR=/path/to/gnulib
 
 The next steps are to get and check other files needed to build,
 and complete the build: