Direnv is extremely verbose

[madjar]

Disclaimer: this boils down to a direnv and print-dev-env issue, but it still relevant to the UX of devenv.

Running direnv allow after running devenv init, on top of the normal output of devenv, we get something like:

direnv: export +AR +AS +CC +CONFIG_SHELL +CXX +DETERMINISTIC_BUILD +DEVENV_DOTFILE +DEVENV_ROOT +DEVENV_STATE +GREET +HOST_PATH +IN_NIX_SHELL +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_STORE +NM +OBJCOPY +OBJDUMP +PYTHONHASHSEED +PYTHONNOUSERSITE +PYTHONPATH +RANLIB +READELF +SIZE +SOURCE_DATE_EPOCH +STRINGS +STRIP +TEMP +TEMPDIR +TMP +TMPDIR +_PYTHON_HOST_PLATFORM +_PYTHON_SYSCONFIGDATA_NAME +buildInputs +buildPhase +builder +cmakeFlags +configureFlags +depsBuildBuild +depsBuildBuildPropagated +depsBuildTarget +depsBuildTargetPropagated +depsHostHost +depsHostHostPropagated +depsTargetTarget +depsTargetTargetPropagated +doCheck +doInstallCheck +dontAddDisableDepTrack +mesonFlags +name +nativeBuildInputs +out +outputs +patches +phases +propagatedBuildInputs +propagatedNativeBuildInputs +shell +shellHook +stdenv +strictDeps +system ~PATH ~XDG_DATA_DIRS

This is very noisy, not very useful, and gives a bad impression.

---

In the end, this is because nix-shell (and nix develop and nix print-dev-env) is designed to "provide the build environment of a derivation", not making shell environments that don't build a derivation.

devshell fixes that by reimplementing mkShell in a way that removes everything that we don't want (doesn't use mkDerivation, and does additional cleanup): https://github.com/numtide/devshell/blob/master/nix/mkNakedShell.nix.

[thenonameguy]

I started development on this branch:
https://github.com/thenonameguy/devenv/tree/naked-shell
The profile abstraction doesn't completely make sense in the context of this project, that has to be reworked.
I included the code from a fork of devshell that has an inputDerivation passthru attribute.
This would allow to trivially implement a devenv cachix-push command that pushes up the CI dependencies.

[domenkozar]

That's really cool @thenonameguy, will you make a PR so we can do some testing?

[thenonameguy]

That's really cool @thenonameguy, will you make a PR so we can do some testing?

That's the plan, will hopefully get to it in the evening. 🙏

[thenonameguy]

@domenkozar please reopen until the revert PR with a solution is found to the issue.
RFC