including gpb as dependency in erlang.mk, fails relx when generating a release

[orotemo]

the usual erlang.mk build process

wget https://erlang.mk/erlang.mk
make -f erlang.mk bootstrap-rel
make -f erlang.mk new-app in=an_app

Then create a Makefile in the root dir:

LOCAL_DEPS = an_app
TEST_DEPS = sync meck

include erlang.mk

and in the new app (named 'an_app') apps/an_app/Makefile:

PROJECT = an_app
PROJECT_DESCRIPTION = New project
PROJECT_VERSION = 0.0.1

DEPS += gpb

include ../../erlang.mk

run make, and it fails. the relx.

Didn't quite get to the root of the problem. sorry about that.

[lukebakken]

Which version of erlang are you using?

[lukebakken]

I'm using 19.1 and getting the following relx error, which appears to be the same as described in erlware/relx#52

gpb-94-make.txt

[tomas-abrahamsson]

@orotemo, did you get the same error as @lukebakken? If so, it seems the vsn in ebin/gpb.app does not get correctly substituted (not at all) when created from src/gpb.app.src. Will take a look.

[orotemo]

@tomas-abrahamsson yes! Thanks.

[tomas-abrahamsson]

Hmm.. preliminary diagnosis, it looks like (a) erlang.mk builds gpb on its own instead of using deps/gpb/Makefile or rebar, and (b) does does not support the {vsn,{cmd,Cmd}} format that gpb uses and rebar supports (as does deps/gpb/Makefile)

I've yet to dig into (a).

This leads to the {cmd,Cmd} landing unmodified as vsn value into deps/gpb/gpb.app, which subsequently---and rightfully, I think---leads to problems when relx sees this.

Don't have any solution yet, though.. (Many Thanks for complete steps to recreate the issue!)

[lukebakken]

Adding NO_AUTOPATCH will cause erlang.mk to use the Makefile from gpb:

https://github.com/lukebakken/gpb_94/blob/master/Makefile#L5

However, I don't see any of the gpb build output in _rel.

Some info here about autopatching.

[lukebakken]

If I add gpb to DEPS in the top-level Makefile, the _rel dir does contain the correct output.

Top level Makefile change.

Output:

$ ll _rel/gpb_94_release/lib/gpb
gpb-3.26.3/   gpb_94-0.0.1/ 

$ ll _rel/gpb_94_release/lib/gpb-3.26.3/
total 24
drwxr-xr-x 6 lbakken lbakken 4096 Oct 20 14:38 .
drwxr-xr-x 6 lbakken lbakken 4096 Oct 20 14:38 ..
drwxr-xr-x 2 lbakken lbakken 4096 Oct 20 14:38 ebin
drwxr-xr-x 2 lbakken lbakken 4096 Oct 20 14:38 include
drwxr-xr-x 3 lbakken lbakken 4096 Oct 20 14:38 priv
drwxr-xr-x 2 lbakken lbakken 4096 Oct 20 14:38 src

[tomas-abrahamsson]

Thanks @lukebakken for digging further!

So one need DEPS += gpb twice, both in apps/an_app/Makefile in the top level Makefile, and in the top level, one also needs NO_AUTOPATCH += gpb. Is this double need of DEPS += gpb common procedure with relx and erlang.mk to get deps into the release or does it need to be addressed somehow? (I don't know; I haven't done this a lot)

[lukebakken]

I really don't know, myself. I've only used erlang.mk for basic projects.

It appears you can remove DEPS from apps/an_app/Makefile and the build succeeds. I'm not sure if it would work if you have code in an_app that depends on gpb, however.

[tomas-abrahamsson]

@orotemo do you think the solution by @lukebakken works well enough?

[orotemo]

@tomas-abrahamsson @lukebakken: sorry for taking so long, and thank you. I managed with this solution. anyway, maybe for @essen this is just a short look to help us understand what needs to change to resolve this.

[essen]

The vsn not being supported is a known issue. The double DEPS is more surprising and sounds like a bug in Erlang.mk.

[tomas-abrahamsson]

How should we move forward on this?

Regarding double DEPS, should be continued as an issue on Erlang.mk?

Regarding vsn, I suppose NO_AUTOPATCH += gpb is ok for you, @orotemo? From a gpb point-of-view this would be preferrable, so that all of gpb builds.

[essen]

Actually I think I see the problem. Autopatch should not run, yet it does because it sees rebar on the following line: https://github.com/tomas-abrahamsson/gpb/blob/master/Makefile#L125

But since rebar is not used, and you don't do anything special with dependencies, we have no reason to run autopatch. I have to fix Erlang.mk to ignore comments when looking for rebar usage.

[tomas-abrahamsson]

Ok, I see. I'll be more or less offline for a few days from now, but rephrasing is quick, so should it still be needed by then, I'll do that.

[essen]

Oddly enough Erlang doesn't care if the vsn key is a tuple when loading the application. That's why it wasn't detected in the nightly build.

The fix is in, you can close this: ninenines/erlang.mk@a8fffe1

Thanks!

[tomas-abrahamsson]

Excellent! Closing. @orotemo, should anything surface, just reopen or open a new.

[essen]

I've opened ninenines/erlang.mk#633 for the double DEPS thing, FYI.