Dialyzer blames Erlang header instead of LFE code

[dendrown]

Hello. There seems to be a strange issue when running rebar3 dialyzer on LFE modules that include an Erlang header file. A warning in the LFE code is flagged as occurring in the Erlang header file.

Take, for example, a project with this source file pets.lfe:

(defmodule pets
  (export
   (test 0)))

(include-file "include/dog.lfe")
(include-lib "include/cat.hrl")

(defun test () 
  "Show the problem."
  (flet (;; CALLED IN MAIN BODY
         (doggie () 
           (io:format "DOG: ~p~n" `(,(make-dog))))

         ;; NEVER CALLED!
         (kitty () 
           (io:format "CAT: ~p~n" `(,(make-cat)))))
    (doggie)))

The dog record is defined in include/dog.lfe:

(defrecord dog
  (name 'fido))

The cat record in include/cat.hrl:

-record(cat,
        {name = pickles}).

Running dialyzer detects that we never call (kitty) from the flet, but dialyzer reports the issue in cat.hrl.

$ rebar3 dialyzer
===> Verifying dependencies...
.
.
.
===> Analyzing 1 files with _build/default/rebar3_26.2.1_plt...

src/include/cat.hrl
Line 8: Function '-lfe-test/0-local-kitty/0-1-'/0 will never be called
===> Warnings written to _build/default/26.2.1.dialyzer_warnings
===> Warnings occurred running dialyzer: 1

I put this example together for this issue, but we have seen the problem a number of times in our larger project. I hope it isn't too obscure, and I appreciate your looking
into it when you get a chance.

[dendrown]

For reference we found the problem on these versions:
lfe: 2.1.2
erlang: 26.2.1
rebar: 3.22.1
rebar_lfe: 0.4.9

We upgraded to rebar 3.23.0 and rebar_lfe 0.4.10 to see if that affected anything. It did not.

We looked into upgrading to lfe 2.1.4, but it breaks our build.

[rvirding]

Why/how does going to lfe 2.1.4 break your build? There is very little that happened between 2.1.3 and 2.14: a small change in the Makefile c97a44f

[dendrown]

So, we were bringing in 2.1.2 via the shortcut in deps in our rebar.config:

diff --git a/rebar.config b/rebar.config
index 77ae003..ef18eb8 100644
--- a/rebar.config
+++ b/rebar.config
@@ -4,7 +4,7 @@
 
 {deps, [
     % NOTE: lfe 2.1.4 is available but may cause build issues (Uncaught error in rebar_core)
-    {lfe,           "2.1.2"},
+    {lfe,           "2.1.4"},
     {lager,         "3.9.2"},
     {jsx,           "3.1.0"},
     {uuid,          "2.0.6", {pkg, uuid_erl}},

But with 2.1.4, it causes an error when we upgrade:

❯ rebar3 unlock --all
❯ rebar3 upgrade --all
===> Verifying dependencies...
===> Package not found in any repo: lfe 2.1.4

So, we do it the long way:

diff --git a/rebar.config b/rebar.config
index 77ae003..08d2374 100644
--- a/rebar.config
+++ b/rebar.config
@@ -4,7 +4,7 @@
 
 {deps, [
     % NOTE: lfe 2.1.4 is available but may cause build issues (Uncaught error in rebar_core)
-    {lfe,           "2.1.2"},
+    {lfe,           {git, "https://github.com/lfe/lfe", {tag, "2.1.4"}}},

We can then unlock & upgrade successfully, but when we try to build our project:

❯ rebar3 compile
===> Verifying dependencies...
===> Uncaught error in rebar_core. Run with DIAGNOSTIC=1 to see stacktrace or consult rebar3.crashdump
===> When submitting a bug report, please include the output of `rebar3 report "your command"`

❯ rebar3 lfe compile
===> Verifying dependencies...
===> Uncaught error in rebar_core. Run with DIAGNOSTIC=1 to see stacktrace or consult rebar3.crashdump
===> When submitting a bug report, please include the output of `rebar3 report "your command"

The resulting rebar3.crashdump looks like this:

Error: {case_clause,
           {error,
               {function_clause,
                   [{lfe_types,to_func_spec,
                        [[[[],[binary]]],11],
                        [{file,
                             "/home/dend/defun/llbeam/_build/default/lib/lfe/src/lfe_types.erl"},
                         {line,340}]},
                    {lists,map,2,[{file,"lists.erl"},{line,1559}]},
                    {lfe_codegen,comp_function_spec,3,
                        [{file,
                             "/home/dend/defun/llbeam/_build/default/lib/lfe/src/lfe_codegen.erl"},
                         {line,406}]},
                    {lists,flatmap_1,2,[{file,"lists.erl"},{line,1579}]},
                    {lists,flatmap_1,2,[{file,"lists.erl"},{line,1579}]},
                    {lfe_codegen,compile_attributes,1,
                        [{file,
                             "/home/dend/defun/llbeam/_build/default/lib/lfe/src/lfe_codegen.erl"},
                         {line,318}]},
                    {lfe_codegen,compile_module,2,
                        [{file,
                             "/home/dend/defun/llbeam/_build/default/lib/lfe/src/lfe_codegen.erl"},
                         {line,90}]},
                    {lfe_codegen,module,2,
                        [{file,
                             "/home/dend/defun/llbeam/_build/default/lib/lfe/src/lfe_codegen.erl"},
                         {line,75}]}]}}}
[{rebar3_lfe_prv_compile,compile_file,3,
                         [{file,"/home/dend/defun/llbeam/_build/default/plugins/rebar3_lfe/src/rebar3_lfe_prv_compile.erl"},
                          {line,103}]},
 {rebar_base_compiler,compile_each,3,
                      [{file,"/home/runner/work/rebar3/rebar3/apps/rebar/src/rebar_base_compiler.erl"},
                       {line,211}]},
 {rebar3_lfe_prv_compile,'-compile_app/2-lc$^0/1-0-',4,
                         [{file,"/home/dend/defun/llbeam/_build/default/plugins/rebar3_lfe/src/rebar3_lfe_prv_compile.erl"},
                          {line,84}]},
 {rebar3_lfe_prv_compile,compile_app,2,
                         [{file,"/home/dend/defun/llbeam/_build/default/plugins/rebar3_lfe/src/rebar3_lfe_prv_compile.erl"},
                          {line,84}]},
 {rebar3_lfe_prv_compile,'-compile/1-lc$^0/1-0-',2,
                         [{file,"/home/dend/defun/llbeam/_build/default/plugins/rebar3_lfe/src/rebar3_lfe_prv_compile.erl"},
                          {line,54}]},
 {rebar3_lfe_prv_compile,compile,1,
                         [{file,"/home/dend/defun/llbeam/_build/default/plugins/rebar3_lfe/src/rebar3_lfe_prv_compile.erl"},
                          {line,54}]},
 {rebar_core,do,2,
             [{file,"/home/runner/work/rebar3/rebar3/apps/rebar/src/rebar_core.erl"},
              {line,155}]},
 {rebar_prv_do,do_task,5,
               [{file,"/home/runner/work/rebar3/rebar3/apps/rebar/src/rebar_prv_do.erl"},
                {line,87}]}]

And here is the info from rebar3 report:

❯ rebar3 report
Rebar3 report
 version 3.23.0
 generated at 2024-07-31T21:37:41+00:00
=================
Please submit this along with your issue at https://github.com/erlang/rebar3/issues (and feel free to edit out private information, if any)
-----------------
Task: 
Entered as:
  
-----------------
Operating System: x86_64-pc-linux-gnu
ERTS: Erlang/OTP 26 [erts-14.2.1] [source] [64-bit] [smp:12:12] [ds:12:12:10] [async-threads:1] [jit:ns]
Root Directory: /usr/lib64/erlang
Library directory: /usr/lib64/erlang/lib
-----------------
Loaded Applications:
bbmustache: 1.12.2
certifi: 2.11.0
cf: 0.3.1
common_test: 1.26
compiler: 8.4.1
crypto: 5.4
cth_readable: 1.5.1
dialyzer: 5.1.2
edoc: 1.2.1
erlware_commons: 1.7.0
eunit: 2.9
eunit_formatters: 0.5.0
getopt: 1.0.2
inets: 9.1
kernel: 9.2
providers: 1.9.0
public_key: 1.15
relx: 4.9.0
sasl: 4.2.1
snmp: 5.15
ssl_verify_fun: 1.1.6
stdlib: 5.2
syntax_tools: 3.1
tools: 3.6

-----------------
Escript path: undefined
Providers:
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