fatal error: folly/folly-config.h: No such file or directory

I have a simple hello world program (test.cpp) that includes FBString.h . When I try to compile it, i get the following error:
` $CXX test.cpp`
`In file included from /usr/include/folly-master/folly/Portability.h:21:0,`

`from /usr/include/folly-master/folly/FBString.h:45,`

`from test.cpp:2:`

`/usr/include/folly-master/folly/portability/Config.h:20:10: fatal error: folly/folly-config.h: No such file or directory`

`#include
`

I do not have the folly-config.h file, but should I? Does this indicate a botched installation? How do I generate this config file?