Revise test script

Author: bocchino

compiler/lib/test/codegen/CppWriter/run

@@ -4,7 +4,6 @@
 
 cpp_doc_ok()
 {
-  ./build && \
   ./hpp > C.hpp && \
   ./cpp > C.cpp && \
   gcc -c C.cpp
@@ -14,4 +13,12 @@ tests="
 cpp_doc_ok
 "
 
-run_suite $tests
+echo 'compiling Scala source'
+if ./build > build_log.txt 2>&1
+then
+  run_suite $tests
+else
+  echo 'compilation failed'
+  echo 'scalac version 2.13.1 or greater required'
+  echo 'see build_log.txt for details'
+fi