Here's what 'git push heroku master' did -- note especially that it installs HTTP::Server::Tiny, which it then doesn't find

heroku-output.txt

$ git push heroku master
Counting objects: 83, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (79/79), done.
Writing objects: 100% (80/80), 2.78 MiB | 353.00 KiB/s, done.
Total 80 (delta 17), reused 0 (delta 0)
remote: Compressing source files... done.
remote: Building source:
remote: 
remote: -----> Fetching set buildpack https://github.com/pnu/heroku-buildpack-rakudo... done
remote: -----> Rakudo perl6 app detected
remote: -----> Vendoring https://heroku-buildpack-rakudo.s3.amazonaws.com/cedar-14/rakudo-2016.03.52.gae.3.a.791.tgz
remote: -----> Current rakudo version is 2016.03.52.gae.3.a.791
remote: ==> Installing Nex from a local directory '.'
remote: ==> Nex depends on HTTP::Server::Tiny
remote: ==> HTTP::Server::Tiny depends on HTTP::Parser, IO::Blob, HTTP::Tinyish
remote: ==> Fetching HTTP::Parser
remote: ==> Building HTTP::Parser
remote: ==> Testing HTTP::Parser
remote: t/01-request-parser.t .. ok
remote: All tests successful.
remote: Files=1, Tests=9,  3 wallclock secs ( 0.02 usr  0.01 sys +  2.61 cusr  0.13 csys =  2.77 CPU)
remote: Result: PASS
remote: ==> Installing HTTP::Parser
remote: ==> Successfully installed HTTP::Parser
remote: ==> Fetching IO::Blob
remote: ==> Building IO::Blob
remote: ==> Testing IO::Blob
remote: t/010_basic.t .. ok
remote: All tests successful.
remote: Files=1, Tests=12,  4 wallclock secs ( 0.04 usr  0.00 sys +  3.46 cusr  0.17 csys =  3.67 CPU)
remote: Result: PASS
remote: ==> Installing IO::Blob
remote: ==> Successfully installed IO::Blob
remote: ==> Fetching HTTP::Tinyish
remote: ==> Building HTTP::Tinyish
remote: ==> Testing HTTP::Tinyish
remote: t/01-basic.t .. ok
remote: All tests successful.
remote: Files=1, Tests=1,  5 wallclock secs ( 0.03 usr  0.01 sys +  4.62 cusr  0.36 csys =  5.02 CPU)
remote: Result: PASS
remote: ==> Installing HTTP::Tinyish
remote: ==> Successfully installed HTTP::Tinyish
remote: ==> Fetching HTTP::Server::Tiny
remote: ==> Building HTTP::Server::Tiny
remote: ==> Testing HTTP::Server::Tiny
remote: t/02-server.t ........... ok
remote: t/04-get.t .............. ok
remote: t/05-post.t ............. ok
remote: t/06-channel.t .......... ok
remote: t/07-io-handle.t ........ ok
remote: t/08-long-req.t ......... ok
remote: t/09-chunked-request.t .. ok
remote: t/10-ise.t .............. ok
remote: t/11-str.t .............. ok
remote: t/12-supply.t ........... ok
remote: All tests successful.
remote: Files=10, Tests=11, 56 wallclock secs ( 0.04 usr  0.01 sys + 54.51 cusr  1.78 csys = 56.34 CPU)
remote: Result: PASS
remote: ==> Installing HTTP::Server::Tiny
remote: ==> Successfully installed HTTP::Server::Tiny
remote: ==> Fetching Nex
remote: ==> Building Nex
remote: ==> Testing Nex
remote: t/conversion-move.t .. ok
remote: t/default-size.t ..... ok
remote: t/placement-move.t ... ok
remote: t/swap.t ............. ok
remote: All tests successful.
remote: Files=4, Tests=41,  5 wallclock secs ( 0.04 usr  0.00 sys +  5.17 cusr  0.38 csys =  5.59 CPU)
remote: Result: PASS
remote: ==> Installing Nex
remote: Use of uninitialized value % of type Any in string context
remote: Any of .^name, .perl, .gist, or .say can stringify undefined things, if needed.  in any load_module at src/Perl6/World.nqp line 986
remote: ==> Successfully installed Nex
remote: 
remote: -----> Discovering process types
remote:        Procfile declares types     -> (none)
remote:        Default types for buildpack -> web
remote: 
remote: -----> Compressing...
remote:        Done: 9.8M
remote: -----> Launching...
remote:        Released v38
remote:        https://limitless-anchorage-20828.herokuapp.com/ deployed to Heroku
remote: 
remote: Verifying deploy... done.
To https://git.heroku.com/limitless-anchorage-20828.git
   bb9f877..67fcf6a  master -> master