Overriding `debug_info` while using `mode` is not working

[eshurakov]

Environment

$ rebar3 report as prod release
Rebar3 report
 version 3.16.1
 generated at 2021-07-19T15:59:23+00:00
=================
Please submit this along with your issue at https://github.com/erlang/rebar3/issues (and feel free to edit out private information, if any)
-----------------
Task: asprodrelease
Entered as:
  asprodrelease
-----------------
Operating System: x86_64-apple-darwin19.6.0
ERTS: Erlang/OTP 23 [erts-11.2.2.3] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1] [hipe] [dtrace]
Root Directory: /usr/local/Cellar/erlang@23/23.3.4.4/lib/erlang
Library directory: /usr/local/Cellar/erlang@23/23.3.4.4/lib/erlang/lib
-----------------
Loaded Applications:
bbmustache: 1.10.0
certifi: 2.6.1
cf: 0.3.1
common_test: 1.20.2.1
compiler: 7.6.9.1
crypto: 4.9.0.2
cth_readable: 1.5.1
dialyzer: 4.3.1.1
edoc: 0.12
erlware_commons: 1.5.0
eunit: 2.6
eunit_formatters: 0.5.0
getopt: 1.0.1
hipe: 4.0.1
inets: 7.3.2.1
kernel: 7.3.1.2
providers: 1.8.1
public_key: 1.10
relx: 4.4.0
sasl: 4.0.2
snmp: 5.8.0.1
ssl_verify_fun: 1.1.6
stdlib: 3.14.2.1
syntax_tools: 2.5
tools: 3.4.4

-----------------
Escript path: undefined
Providers:
  app_discovery as clean compile compile cover ct deps dialyzer do edoc escriptize eunit get-deps help install install_deps list lock new path pkgs release relup report repos shell state tar tree unlock update upgrade upgrade upgrade version xref

Current behaviour

I created a new app using rebar3 new app test and updated rebar3.conf:

{erl_opts, [debug_info]}.
{deps, []}.

{shell, [
  % {config, "config/sys.config"},
    {apps, [test]}
]}.

{relx, [{release, {test, "0.1"}, [sasl, test]},
         {mode, dev}
]}.

{profiles, [{prod, [
              {relx, [
                {mode, prod},
                {debug_info, keep}
              ]}
            ]}
]}.

Following https://rebar3.org/docs/deployment/releases/#modes I added the following to the production profile to keep debug information:

{mode, prod},
{debug_info, keep}

When I build my app using rebar3 as prod release I see that debug information is not kept. I tested it by opening the console: _build/prod/rel/test/bin/test console and trying to get attributes of test_sup.erl:

> test_sup:module_info().
[{module,test_sup},
 {exports,[{start_link,0},
           {init,1},
           {module_info,0},
           {module_info,1}]},
 {attributes,[]},
 {compile,[]},
 {native,false},
 {md5,<<48,223,167,10,92,6,166,197,38,140,210,83,191,40,
        77,59>>}]

Note that attributes and compile lists are empty.

To see what's going on I added some debug information to rebar_relx.erl to see what the config looks like before it is converted to state:

erlang:display(RelxConfig2),
{ok, RelxState} = rlx_config:to_state(RelxConfig2),

> rebar3 as prod release

[{mode,prod},{output_dir,".../test/_build/prod/rel"},{overlay_vars_values,[{profile_string,"prod"}]},{overlay_vars,[{base_dir,".../test/_build/prod"}]},{overlay,[]},{debug_info,keep},{mode,dev},{mode,prod},{release,{test,"0.1"},[sasl,test]}]

I believe in the end {mode,prod} overrides everything.

Expected behaviour

{debug_info, keep} is applied after {mode,prod} and debug info is kept.

[ferd]

Yeah that sounds like a bug. While {mode, prod} does imply [{include_src, false}, {debug_info, strip}, {include_erts, true}, {dev_mode, false}], we should ideally be able to know that one is more specific than the other.

[hejin1026]

i found the same problem when i use relup. it not work. but i need debu_info. so i have to try to use other version of rebar3. the last, i found only rebar3 of 3.13.3 work. 3.14-3.16.1 not work

[hejin1026]

even throung [{include_src, false}, {debug_info, strip}, {include_erts, true}, {dev_mode, false}] instead of {mode, prod}, it also not work

[tsloughter]

Can you try:

{debug_info, keep},
{mode, prod}

That'll tell me quick if its just an issue of mode expanding in a way that it is keeping the mode debug_info instead of the one from the config.

[ferd]

^ that's what the opening post is mentioning happening

[tsloughter]

The opening post shows the result is it still being set to strip in the list of args, but not that it is the order that causes this. But yea, I suspect it is and should be a simple fix in relx.

[weiss]

AFAICS, the problem is only with profiles. E.g., with the following rebar.config, using rebar3 3.17.0:

{relx,
 [{release, {test, "0.1.0"}, [test, sasl]},
  {mode, dev},
  {include_erts, "/nonexistent"}]}.

{profiles, [{foo, [{relx,
                    [{mode, dev},
                     {include_erts, "/nonexistent"}]}]}]}.

… rebar3 release works as expected (i.e., complains about /nonexistent), while rebar3 as foo release doesn't try to include ERTS. Even if you remove either of the two {mode, dev} options, the behavior remains exactly that way. Only if you remove both {mode, dev} settings, rebar as foo release works as expected.