Erlexec compile error in mix grisp.deploy

In grisp_tools 2.7.0 erlexec is introduced in the dependency tree, but somehow mix cannot build it.

mix grisp.deploy                                                                                                                                                   
===> Error reading file /Users/***/Desktop/grisp/testex/_build/dev/lib/erlexec/mix.rebar.config: 8: cannot translate from UTF-8
** (Mix) Could not compile dependency :erlexec, "/Users/***/.asdf/installs/elixir/1.16.3-otp-26/.mix/elixir/1-16/rebar3 bare compile --paths /Users/***/Desktop/grisp/testex/_build/dev/lib/*/ebin" command failed. Errors may have been logged above. You can recompile this dependency with "mix deps.compile erlexec --force", update it with "mix deps.update erlexec" or clean it with "mix deps.clean erlexec"

This is the generated file _build/dev/lib/erlexec/mix.rebar.config

{hex,[{doc,ex_doc}]}.
{ex_doc,[{extras,[{"README.md",#{title => "Overview"}},
                  {"LICENSE",#{title => "License"}}]},
         {main,"README.md"},
         {authors,["Serge Aleynikov"]},
         {source_url,"https://github.com/saleyn/erlexec"}]}.
{erl_opts,[debug_info,warn_export_all]}.
{edoc_opts,[{def,{vsn,"fatal: .git non � un repository Git (n� lo � alcuna delle directory genitrici)"}}]}.
{plugins,[rebar3_hex,rebar3_ex_doc]}.
{post_hooks,[{"(freebsd|netbsd|openbsd)",clean,"gmake -C c_src clean"},
             {"(linux|darwin|solaris)",clean,"make -C c_src clean"}]}.
{pre_hooks,[{"(freebsd|netbsd|openbsd)",compile,"gmake -C c_src"},
            {"(linux|darwin|solaris)",compile,"make -C c_src"}]}.
{overrides,[]}.

Line 8 is giving error, why is there that edoc_opts list? the vsn string is a git error so no wonder it fails...