With FIPS mode enabled, Foreman won't run. Results are as follows:

foreman-rake apiepie:cache
Apipie cache enabled but not present yet. Run apipie:cache rake task to speed up API calls.
md5_dgst.c(80): OpenSSL internal error, assertion failed: Digest MD5 forbidden in FIPS mode!
/tmp/tmp.mrjvUccRvF: line 1: 25276 Aborted rake apipie:cache

Specifically this is because MD5 is not a valid cipher with FIPS enabled. After some digging, it seems that stems from Rack.
Check here: https://github.com/rack/rack/blob/master/lib/rack/etag.rb#L2
And here: https://github.com/rack/rack/blob/master/lib/rack/etag.rb#L68

Hopefully there aren't many cipher issues but I can't continue to find out until this one gets resolved.