force .a file creation thru anonymous global variable

src/units/dummy.cpp

@@ -2,3 +2,11 @@
 // otherwise units does not compile reliably on all platforms
 // and the pros conductor will not let you create a template if there is
 // no .a file
+
+// a global, volatile variable in an anonymous namespace
+// its put in an anonymous namespace to guarantee that there won't be any
+// linker errors
+// 10/10 codebase (i don't feel like PRing a fix to PROS, make is scary)
+namespace {
+volatile char dummy_var;
+}