[doit] Check for makeinfo
diff --git a/doit b/doit
index 1ddd447..d8dc0c3 100755
--- a/doit
+++ b/doit
@@ -121,6 +121,11 @@
     exit 1
 fi
 
+if [ -z $(which makeinfo) ]; then
+    echo makeinfo not found. On debian/ubuntu this is provided by the texinfo package.
+    exit 1
+fi
+
 export CC="cc"
 export CXX="c++"