Add support for rebar3 - remove use of rebar2 port compiler config

[Vagabond]

Rebar3 doesn't include a port compiler because it turns out it is too
brittle and unportable. Switch to a Makefile via a compile hook instead
to make things compatible with both rebar2 and rebar3.

[cmeiklejohn]

Hrm.

[cmeiklejohn@ChristophersMBP eleveldb ((230111a...))]$ ./rebar -v
ERROR: Failed to load /Users/cmeiklejohn/Documents/eleveldb/rebar.config: {error,
                                                                           {32,
                                                                            file,
                                                                            {error,
                                                                             {badmatch,
                                                                              false},
                                                                             [{erl_eval,
                                                                               expr,
                                                                               3,
                                                                               []}]}}}

[Vagabond]

It doesn't happen for me, line 32 of the rebar.config seems ok to me?

[cmeiklejohn]

[cmeiklejohn@ChristophersMBP eleveldb ((230111a...))]$ git status
HEAD detached at helium/adt-rebar3
nothing to commit, working directory clean

Did you try the included rebar or are you using your own rebar?

[Vagabond]

I'm using the included one

git status
On branch adt-rebar3
Your branch is up-to-date with 'origin/adt-rebar3'.
nothing to commit, working directory clean

erl
Erlang R16B02-basho4 (erts-5.10.3) [source] [64-bit] [smp:8:8] [async-threads:10] [hipe] [kernel-poll:false]

[cmeiklejohn]

[cmeiklejohn@ChristophersMBP eleveldb ((230111a...))]$ erl -v
Erlang R16B02-basho6 (erts-5.10.3) [source] [64-bit] [smp:4:4] [async-threads:10] [hipe] [kernel-poll:false] [frame-pointer] [dtrace]

[cmeiklejohn]

[cmeiklejohn@ChristophersMBP eleveldb ((230111a...))]$ git checkout develop
Previous HEAD position was 230111a... Add support for rebar3 - remove use of rebar2 port compiler config
Switched to branch 'develop'
Your branch is up-to-date with 'origin/develop'.
[cmeiklejohn@ChristophersMBP eleveldb (develop)]$ make
./rebar get-deps
==> eleveldb (get-deps)
Cloning into 'leveldb'...
Note: checking out '2.0.0'.

Is there some sort of weird character encoding in that rebar file or something?

[cmeiklejohn]

I can reproduce this problem on the develop branch by removing the port_env section of the rebar.config file and running ./rebar compile.

[Vagabond]

1> file:consult("rebar.config").
{ok,[{eunit_opts,[verbose]},
     {so_name,"eleveldb.so"},
     {xref_checks,[undefined_function_calls]},
     {port_sources,["c_src/*.cc"]},
     {erl_opts,[warnings_as_errors,
                {parse_transform,lager_transform},
                debug_info]},
     {deps,[{cuttlefish,".*",
                        {git,"git://github.com/basho/cuttlefish.git",
                             {branch,"develop"}}}]},
     {pre_hooks,[{'get-deps',"c_src/build_deps.sh get-deps"},
                 {compile,"c_src/build_deps.sh"},
                 {compile,"make -C c_src"}]},
     {post_hooks,[{clean,"c_src/build_deps.sh clean"}]}]}

[cmeiklejohn]

Adding {port_env, []} resolves the problem, but omitting port_env triggers the parse failure.

[tsloughter]

You can now simply add this to your config that lists eleveldb as a dep to be able to build eleveldb: https://gist.github.com/tsloughter/8135f58949e7a3144bf7

But eleveldb's port config stuff is even legacy by rebar2's standards. I had to update @blt's port compiler plugin to support it. Also covered in this PR #84

So something to clean up eleveldb building would be nice whether it is updating the rebar config or going with the Makefile :)

[marianoguerra]

I'm trying to port some stuff to rebar3 and this is one of the stoppers at the moment 👍