+# tryTimes tries to run its third argument multiple times, until it
+# succeeds. Don't call it directly; call try10Times instead.
+# The first and second argument to tryTimes are lists of values.
+# The length of the first argument is the number of times we have
+# already tried. The length of the second argument is the number more
+# times we will try.
+tryTimes = $(if $2, \
+ { echo 'Try $(words x $1): $3' ; $3 ; } || \
+ $(call tryTimes,x $1,$(wordlist 2,$(words $2),$2),$3), \
+ )
+
+# Try to run the argument 10 times. If all 10 fail, fail.
+try10Times = $(call tryTimes,,x x x x x x x x x x,$1) { echo Failed; false; }