Warnings about OTP-PUB-KEY.erl and PKCS-FRAME.erl

[SebCav]

Hi,
when creating a release, rebar3 prints a couple of warnings which I don't understand:

===> Assembling release myproject-2.0.0...
===> Warnings generating release:
WARNING public_key: Source code not found: 'OTP-PUB-KEY'.erl
WARNING public_key: Source code not found: 'PKCS-FRAME'.erl

Could someone please explain me what this is about?

[ferd]

Not necessarily. This appears to be about the release mechanism looking for the source files matching compiled modules and not being able to find them. In this case the public_key library ships with OTP.

[SebCav]

Very strange...

[BM - OTP19.3 - root]:/# find -iname "OTP-PUB-KEY.erl" 2>>/dev/null
./usr/lib/erlang/lib/public_key-1.4/asn1/OTP-PUB-KEY.erl
[BM - OTP19.3 - root]:/# ls /root/build/myproject/_build/prod/rel/myproject/lib/public_key-1.4/
ebin  include  src
[BM - OTP19.3 - root]:/# ls /usr/lib/erlang/lib/public_key-1.4/
asn1  ebin  include  src

I'm using an old building machine based on a Debian 8 with OTP19.3 installed via Erlang Solution's deb, and the latest rebar3. I suppose this is a relx issue which is not copying the asn1 directory next to the others... right?

[ferd]

yeah. See also the other discussion at #2494 (reply in thread) which has existing context for this.

[SebCav]

Ok thank you

[p-kraszewski]

I've hit the problem.

Some more exploring gained this: Files being looked for are, for example 'OTP-PUB-KEY'.erl.

If you look carefully, those names have ticks ' burned into them. It is probably a result of -module('OTP-PUB-KEY'). part of OTP-PUB-KEY.erl file. Module name is "ticked" here to make it a proper atom (-module(). expects atom).

Some dependency seeking procedure doesn't notice, that ticks don't become the part of the .beam/.erl filename.

[p-kraszewski]

OK, after some extensive patching with io:format of lib/sasl/src/systools_make.erl I found:

• Ticks in error message are due to using ~w in format string - the file name is actually correct. My initial diagnosis was wrong.
• The error manifests in default profile (non-prod), which attempts to copy source files to respective library-VER/src directories of release.
• The two missing file errors are due to the fact, that both OTP-PUB-KEY.erl and PKCS-FRAME.erl reside in lib/public_key-VER/asn1 directory, not in lib/public_key-VER/src.

The error is harmless from release's point of view -- the only drawback is incomplete source tree, if release creates it.

[tsloughter]

Oh, thanks for the digging! I guess I need to check if there is a built in way to Erlang, maybe in code, to get all source dirs of an application so that asn1 would be copied.

[tsloughter]

Ugh, I'm guessing not, since even filelib:find_source can't find the erl file for those beam files:

> filelib:find_source("/home/tristan/.cache/erlup/otps/OTP-24.0.1/dist/lib/erlang/lib/public_key-1.11/ebin/PKCS-FRAME.beam").
{error,not_found}

[ferd]

There are some severe limitations about anything OTP does to try and find source files. erlang/otp#5302 was one specific one, where only subdirectories of source files (which are in src/ and e_src/) get supported (the PR linked was me adding a recursive search for them). Anything that's in asn1/ is not gonna be picked up without patching OTP as well.

[p-kraszewski]

I suppose dropping those autogenerated .erl/.hrl files into respective src/include directories could solve the problem.