lorri + direnv reloads environment after every command

Describe the bug

When running a command in a directory with a lorri + direnv setup, lorri will rebuild the derivation and reload the environment, even when there were no changes to shell.nix

To Reproduce Steps to reproduce the behavior:

Create an .envrc file

eval "$(lorri direnv)"

Create a shell.nix

with import <nixpkgs> {};

stdenv.mkDerivation {
  name = "work-dev";
  buildInputs = with pkgs; [
    cargo clangStdenv rust-analyzer rustc rustfmt cargo-expand

    openjdk gradle cmake elixir
  ];
}

Run direnv allow

 ❤ (tempest) ~/P/c/ooo> cd ooo/                                                                                                                       
direnv: loading ~/Projects/clients/ooo/ooo/.envrc
direnv: export +AR +AS +CC +CMAKE_INCLUDE_PATH +CMAKE_LIBRARY_PATH +CMAKE_PREFIX_PATH +CONFIG_SHELL +CXX +ERL_LIBS +HOST_PATH +IN_LORRI_SHELL +IN_NIX_SHELL +JAVA_HOME +LD +NIX_BINTOOLS +NIX_BINTOOLS_WRAPPER_TARGET_HOST_x86_64_unknown_linux_gnu +NIX_BUILD_CORES +NIX_BUILD_TOP +NIX_CC +NIX_CC_WRAPPER_TARGET_HOST_x86_64_unknown_linux_gnu +NIX_CFLAGS_COMPILE +NIX_ENFORCE_NO_NATIVE +NIX_HARDENING_ENABLE +NIX_INDENT_MAKE +NIX_LDFLAGS +NIX_LOG_FD +NIX_STORE +NM +OBJCOPY +OBJDUMP +RANLIB +READELF +SIZE +SOURCE_DATE_EPOCH +STRINGS +STRIP +allowSubstitutes +buildInputs +builder +configureFlags +depsBuildBuild +depsBuildBuildPropagated +depsBuildTarget +depsBuildTargetPropagated +depsHostHost +depsHostHostPropagated +depsTargetTarget +depsTargetTargetPropagated +doCheck +doInstallCheck +extraClosure +name +nativeBuildInputs +origArgs +origBuilder +origExtraClosure +origOutputs +origPATH +origSystem +out +outputs +patches +preHook +preferLocalBuild +propagatedBuildInputs +propagatedNativeBuildInputs +shell +stdenv +strictDeps +system ~PATH ~XDG_DATA_DIRS
 ❤ (tempest) ~/P/c/o/ooo> cat shell.nix                                                                                       lorri-keep-env-hack-ooo
with import <nixpkgs> {};

stdenv.mkDerivation {
  name = "ooo";
  buildInputs = with pkgs; [
    cargo clangStdenv rust-analyzer rustc rustfmt cargo-expand

    openjdk gradle cmake elixir
  ];
}
direnv: loading ~/Projects/clients/ooo/ooo/.envrc
direnv: export +AR +AS +CC +CMAKE_INCLUDE_PATH +CMAKE_LIBRARY_PATH +CMAKE_PREFIX_PATH +CONFIG_SHELL +CXX +ERL_LIBS +HOST_PATH +IN_LORRI_SHELL +IN_NIX_SHELL +JAVA_HOME +LD +NIX_BINTOOLS +NIX_BINTOOLS_WRAPPER_TARGET_HOST_x86_64_unknown_linux_gnu +NIX_BUILD_CORES +NIX_BUILD_TOP +NIX_CC +NIX_CC_WRAPPER_TARGET_HOST_x86_64_unknown_linux_gnu +NIX_CFLAGS_COMPILE +NIX_ENFORCE_NO_NATIVE +NIX_HARDENING_ENABLE +NIX_INDENT_MAKE +NIX_LDFLAGS +NIX_LOG_FD +NIX_STORE +NM +OBJCOPY +OBJDUMP +RANLIB +READELF +SIZE +SOURCE_DATE_EPOCH +STRINGS +STRIP +allowSubstitutes +buildInputs +builder +configureFlags +depsBuildBuild +depsBuildBuildPropagated +depsBuildTarget +depsBuildTargetPropagated +depsHostHost +depsHostHostPropagated +depsTargetTarget +depsTargetTargetPropagated +doCheck +doInstallCheck +extraClosure +name +nativeBuildInputs +origArgs +origBuilder +origExtraClosure +origOutputs +origPATH +origSystem +out +outputs +patches +preHook +preferLocalBuild +propagatedBuildInputs +propagatedNativeBuildInputs +shell +stdenv +strictDeps +system ~PATH ~XDG_DATA_DIRS

Expected behavior

lorri rebuilds my environment whenever a change was made to shell.nix

Metadata

$ lorri info
lorri version: 1.3
GC roots exist, shell_gc_root: "/home/.cache/lorri/gc_roots/7c3b2e96948f6bb1e93d5fb988de6702/gc_root/shell_gc_root"

$ uname -a
Linux tempest 5.4.100 #1-NixOS SMP Tue Feb 23 14:02:26 UTC 2021 x86_64 GNU/Linux

Additional context

target / lorri

lorri + direnv reloads environment after every command #499