Add SHELL = /bin/sh.

diff --git a/GNUmakefile b/GNUmakefile
index 861ce8e38fd928468c3b90ed3806bf066c72e59a..0f4e21c69bb14265f878025fe2b9ccd1246404a8 100644 (file)
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -4,6 +4,10 @@
 # It is necessary if you want to build targets usually of interest
 # only to the maintainer.
 
+# Systems where /bin/sh is not the default shell need this.  The $(shell)
+# command below won't work with e.g. stock DOS/Windows shells.
+SHELL = /bin/sh
+
 have-Makefile := $(shell test -f Makefile && echo yes)
 
 # If the user runs GNU make but has not yet run ./configure,