Different behaviour when producing annotations with Erlang Typer

Question

I am using the typer_core module of Dialyzer to automatically infer typespecs. However, I am obtaining different behaviour based on whether the files specified are prepended with the . character or not. The behaviour described below only affects files located in the directory where the typer command is run; files in child directories are processed as expected by Typer.

Consider the module test.erl:

-module(test).

is_a_ok(a) -> ok.

The behaviour below is produced when evaluating the following expressions on the REPL:

% Prepending with the '.' character.

% Creates the file ./typer_ann/test.ann.erl, but is NOT annotated.
typer_core:run(#{mode => annotate, files => ["./test.erl"]}). 
      Processing file: "./test.erl"
             Saved as: "./typer_ann/test.ann.erl"

% Does NOT annotate the file ./test.erl.
typer_core:run(#{mode => annotate_in_place, files => ["./test.erl"]}). 
      Processing file: "./test.erl"
             Saved as: "./test.erl"


% Without the '.' character.

% Creates the file ./typer_ann/test.ann.erl, and is annotated.
typer_core:run(#{mode => annotate, files => ["test.erl"]}).  
      Processing file: "test.erl"
             Saved as: "./typer_ann/test.ann.erl"

% Annotates the file ./test.erl.
typer_core:run(#{mode => annotate_in_place, files => ["test.erl"]}).
      Processing file: "test.erl"
             Saved as: "test.erl"

Using . in conjunction with the files_r key (equivalent to the -r command line switch) processes directories recursively. I observed the same behaviour described above when attempting to annotate files with the files_r key, specifying . as the starting directory:

% Does NOT annotate any of the files in the current directory.
typer_core:run(#{mode => annotate_in_place, files_r => ["."]}).
      Processing file: "./test.erl"
             Saved as: "./test.erl"

This can be reproduced using Typer on the command line:

# Does NOT annotate the file ./test.erl.
$ typer --annotate-in-place ./test.erl
      Processing file: "./test.erl"
             Saved as: "./test.erl"

# Does NOT annotate any of the files in the current directory.
$ typer --annotate-in-place -r .
      Processing file: "./test.erl"
             Saved as: "./test.erl"

Note that, however, *.erl files in child directories do get annotated in the first and last examples, i.e. using typer_core:run(#{mode => annotate_in_place, files_r => ["."]}) and typer --annotate-in-place -r . The following examples also work:

# Annotates the file ./test.erl (no . in front of the file name).
$ typer --annotate-in-place test.erl
      Processing file: "test.erl"
             Saved as: "test.erl"

# Annotates the file test.erl (. in front of the directory, one directory up).
$ typer --annotate-in-place ./typer_test/test.erl
      Processing file: "./typer_test/test.erl"
             Saved as: "./typer_test/test.erl"

I might be missing something and would appreciate any suggestions regarding this behaviour. I am using OTP 25.0.4.