Empty source AST

[williamthome]

I have failling actions on this PR by running rebar3 ex_doc:

===> Running ex_doc for template_compiler
===> warning: the VM is running with native name encoding of latin1 which may cause Elixir to malfunction as it expects utf8. Please ensure your locale is set to UTF-8 (which can be verified by running "locale" in your shell) or set the ELIXIR_ERL_OPTIONS="+fnu" environment variable
** (ArgumentError) errors were found at the given arguments:

  * 1st argument: not a nonempty list

    :erlang.hd([])
    (ex_doc 0.31.2) lib/ex_doc/language/source.ex:2[19](https://github.com/zotonic/template_compiler/actions/runs/8827353833/job/24236586917?pr=48#step:8:20): ExDoc.Language.Source.find_ast/3
    (ex_doc 0.31.2) lib/ex_doc/language/erlang.ex:167: ExDoc.Language.Erlang.type_data/2
    (ex_doc 0.31.2) lib/ex_doc/retriever.ex:388: ExDoc.Retriever.get_type/5
    (ex_doc 0.31.2) lib/ex_doc/retriever.ex:378: anonymous fn/6 in ExDoc.Retriever.get_types/4
    (elixir 1.16.0) lib/enum.ex:[25](https://github.com/zotonic/template_compiler/actions/runs/8827353833/job/24236586917?pr=48#step:8:26)28: Enum."-reduce/3-lists^foldl/2-0-"/3
    (ex_doc 0.31.2) lib/ex_doc/retriever.ex:377: ExDoc.Retriever.get_types/4
    (ex_doc 0.31.2) lib/ex_doc/retriever.ex:155: ExDoc.Retriever.generate_node/3

===> 
make: *** [GNUmakefile:43: edoc] Error 1
Error: Process completed with exit code 2.

That's the line that is causing the error:

ex_doc/lib/ex_doc/language/source.ex

Line 219 in 72bb758

filtermap_ast(ast, source_basedir, fun) |> hd()

I did not look at why the AST it's empty or if it can be empty.

[josevalim]

Either source file was compiled with debug_info or you have entries in your docs chunk for types that do not exist. In any case, we can likely improve the error message here.

[josevalim]

I have improved the error messages on main. It may help pinpoint the root cause.

[williamthome]

@josevalim how can I use the main version on this rebar.config file?

[wojtekmach]

Please try:

{project_plugins, [{rebar3_ex_doc, {git, "git://github.com/starbelly/rebar3_ex_doc.git"}}]}.

[williamthome]

Please try:

{project_plugins, [{rebar3_ex_doc, {git, "git://github.com/starbelly/rebar3_ex_doc.git"}}]}.

Hmm I think this is related to rebar3_ex_doc plugin and not to ex_doc itself.
I found this on rebar3 docs. Will try.
Thank you!

[williamthome]

I'm closing this issue because now all checks have passed.
Thanks @josevalim @wojtekmach !