I'm using macOS Catalina and trying to execute a simple command raku -e "use Cro::HTTP::Route". I will get a message [1] 19228 abort raku in the Zsh shell or Abort trap: 6 in the Bash shell. I face the same issue when using an OpenSSL module like raku -e "use OpenSSL::Stack".
> raku -v
This is Rakudo version 2019.11-268-g0e4f8351e built on MoarVM version 2019.11-92-gd7b6855d3 implementing Perl 6.d.
> zef info OpenSSL
OpenSSL:ver<0.1.22>:auth<github:sergot>
> zef info cro
cro:ver<0.8.2>
It happens because of the OpenSSL module cannot find OpenSSL_version_num function in libssl.dylib in the default paths and crashes.
To fix it you need to install openssl through brew and make a link for libssl.dylib library:
brew install openssl
ln -s /usr/local/opt/openssl/lib/libssl.dylib /usr/local/lib/