Mix release fails to start

I am trying to build a mix release but it is failing on start

MIX_ENV=prod mix release papercups

SECRET_KEY_BASE="test"  DATABASE_URL=ecto://postgres:postgres@localhost/chat_api_dev _build/prod/rel/papercups/bin/papercups start

chat_api: generated priv/static/swagger.json
* assembling papercups-0.1.0 on MIX_ENV=prod
* using config/releases.exs to configure the release at runtime

Release created at _build/prod/rel/papercups!

    # To start your system
    _build/prod/rel/papercups/bin/papercups start

Once the release is running:

    # To connect to it remotely
    _build/prod/rel/papercups/bin/papercups remote

    # To stop it gracefully (you may also send SIGINT/SIGTERM)
    _build/prod/rel/papercups/bin/papercups stop

To list all commands:

    _build/prod/rel/papercups/bin/papercups

20:42:39.224 [info] Running ChatApiWeb.Endpoint with cowboy 2.8.0 at :::4000 (http)
20:42:39.226 [info] Application chat_api exited: ChatApi.Application.start(:normal, []) returned an error: shutdown: failed to start child: ChatApiWeb.Endpoint
    ** (EXIT) an exception was raised:
        ** (FunctionClauseError) no function clause matching in Kernel.=~/2
            (elixir 1.10.4) lib/kernel.ex:2011: Kernel.=~(nil, ~r/[^:]:\d/)
            (phoenix 1.5.5) lib/phoenix/endpoint/supervisor.ex:352: Phoenix.Endpoint.Supervisor.build_url/2
            (phoenix 1.5.5) lib/phoenix/endpoint/supervisor.ex:288: Phoenix.Endpoint.Supervisor.url/1
            (phoenix 1.5.5) lib/phoenix/config.ex:54: Phoenix.Config.cache/3
            (phoenix 1.5.5) lib/phoenix/endpoint/supervisor.ex:483: Phoenix.Endpoint.Supervisor.log_access_info/2
            (phoenix 1.5.5) lib/phoenix/endpoint/supervisor.ex:17: Phoenix.Endpoint.Supervisor.start_link/3
            (stdlib 3.13) supervisor.erl:385: :supervisor.do_start_child_i/3
            (stdlib 3.13) supervisor.erl:371: :supervisor.do_start_child/2
{"Kernel pid terminated",application_controller,"{application_start_failure,chat_api,{{shutdown,{failed_to_start_child,'Elixir.ChatApiWeb.Endpoint',{'EXIT',{function_clause,[{'Elixir.Kernel','=~',[nil,#{'__struct__' => 'Elixir.Regex',opts => <<>>,re_pattern => {re_pattern,0,0,0,<<69,82,67,80,76,0,0,0,0,0,0,0,65,0,0,0,255,255,255,255,255,255,255,255,0,0,58,0,0,0,0,0,0,0,64,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,131,0,8,31,58,29,58,7,120,0,8,0>>},re_version => {<<\"8.44 2020-02-12\">>,little},source => <<\"[^:]:\\d\">>}],[{file,\"lib/kernel.ex\"},{line,2011}]},{'Elixir.Phoenix.Endpoint.Supervisor',build_url,2,[{file,\"lib/phoenix/endpoint/supervisor.ex\"},{line,352}]},{'Elixir.Phoenix.Endpoint.Supervisor',url,1,[{file,\"lib/phoenix/endpoint/supervisor.ex\"},{line,288}]},{'Elixir.Phoenix.Config',cache,3,[{file,\"lib/phoenix/config.ex\"},{line,54}]},{'Elixir.Phoenix.Endpoint.Supervisor',log_access_info,2,[{file,\"lib/phoenix/endpoint/supervisor.ex\"},{line,483}]},{'Elixir.Phoenix.Endpoint.Supervisor',start_link,3,[{file,\"lib/phoenix/endpoint/supervisor.ex\"},{line,17}]},{supervisor,do_start_child_i,3,[{file,\"supervisor.erl\"},{line,385}]},{supervisor,do_start_child,2,[{file,\"supervisor.erl\"},{line,371}]}]}}}},{'Elixir.ChatApi.Application',start,[normal,[]]}}}"}
Kernel pid terminated (application_controller) ({application_start_failure,chat_api,{{shutdown,{failed_to_start_child,'Elixir.ChatApiWeb.Endpoint',{'EXIT',{function_clause,[{'Elixir.Kernel','=~',[nil,

Crash dump is being written to: erl_crash.dump...done

The code is on this branch to repro https://github.com/papercups-io/papercups/tree/prod-self-deploy-docker

I m not too sure how to debug this would love any feedback or help
Thanks!