On Linux, if you compile the reducer example with -fcilk-stub to create a serialization, compilation will fail.
Closer examination of the various reducer header files revealed the following comment in several:
/////////////////////////////////////////////////////////////////////////// // Support for backwards-compatibility with Cilk 1.0 reducers. // DO NOT USE THESE INTERFACES FOR NEW CODE ///////////////////////////////////////////////////////////////////////////
If the code to which these comments is attached in the reducer include files is commented out, then the serializations work, as long as you have a version of libstdc++ that is new enough for the cilk++ compiler installed. The reducer serialization failed on my local Red Hat system with the error message
./reducer: /usr/lib64/libstdc++.so.6: version `GLIBCXX_3.4.9' not found (required by ./reducer)
even though the cilk++ version compiled without -fcilk-stub ran fine.
I built gcc-4.2.4 (compatible with what the cilk++ installation was based upon) and put the path to the installations lib64 directory on my LD_LIBRARY_PATH and that fixed things. Your release/installation notes should indicate version requirements for libstdc++ and how to satisfy them.