I've just tried to run the simple HTTP server from the language documentation. The program fails with an error.
/usr/bin/ld: cannot find -lssl
collect2: error: ld returned 1 exit status
Error: execution of command failed with code: 1: `cc -o "/home/rasmus/dev/crystal/projects/hello/.crystal/crystal-run-hello.tmp" "${@}" -rdynamic -lssl -levent -lrt -lpcl -lpcre -lgc -lpthread -ldl`
The program has been copy-pasted from the documentation.
I can confirm that the program did/does run on my guest machine, but not on my host. Both are Ubuntu 14.04.3 installs.