Merge from master.

--HG--
branch : default-branch

diff --cc Makefile
index ebba091,af143bc..282ff0a
--- 1/Makefile
--- 2/Makefile
+++ b/Makefile
@@@ -25,8 -25,26 +25,26 @@@ BUILDDIR = $(ACK_TEMP_DIR)/ack-buil
  # What build flags do you want to use?
  
  CFLAGS = -g
 -LDFLAGS = 
 +LDFLAGS =
  
+ # Various commands.
+ 
+ AR = ar
+ CC = gcc
+ 
+ # Which build system to use; use 'ninja' or 'make' (in lower case). Leave
+ # blank to autodetect.
+ 
+ BUILDSYSTEM =
+ 
+ # Build flags for ninja.
+ 
+ NINJAFLAGS =
+ 
+ # Build flags for make.
+ 
+ MAKEFLAGS = -r
+ 
  # ======================================================================= #
  #                         END OF CONFIGURATION                            #
  # ======================================================================= #