The CPP_PLATFORM variables comes from configure.ac. AC_SUBST replaces occurrences of variables wrapped in @ characters, so change the wrapping of CPP_PLATFORM in Makefile.am to use @

Author: charlesnicholson

Makefile.am

@@ -50,7 +50,7 @@ lib_libCppUTest_a_SOURCES = \
 	src/CppUTest/TestRegistry.cpp \
 	src/CppUTest/TestResult.cpp \
 	src/CppUTest/Utest.cpp \
-	src/Platforms/$(CPP_PLATFORM)/UtestPlatform.cpp
+	src/Platforms/@CPP_PLATFORM@/UtestPlatform.cpp
 
 include_cpputestdir = $(includedir)/CppUTest