fix(direnv): set DEVBOX_SHELL_ENABLED when entering env via shellenv --init-hook

[mikeland73]

Summary

Fixes #2746.

When using direnv to load a Devbox environment, $DEVBOX_SHELL_ENABLED was never set, even though the documentation states it is "automatically set to 1 when you start a shell, run a script, or start services."

The direnv integration loads the environment by evaluating devbox shellenv --init-hook (see internal/devbox/generate/tmpl/envrcContent.tmpl). That code path runs through Devbox.EnvExports, which — unlike Shell() and RunScript() — never set DEVBOX_SHELL_ENABLED. So echo $DEVBOX_SHELL_ENABLED printed nothing in a direnv-activated shell.

Fix

Set DEVBOX_SHELL_ENABLED=1 in EnvExports when init hooks are run, mirroring what Shell() and RunScript() already do.

The assignment is gated on RunHooks on purpose:

• The direnv integration uses devbox shellenv --init-hook (RunHooks = true) → now sets the variable. ✅
• The global integration devbox global shellenv runs in every shell and does not pass --init-hook (RunHooks = false) → still does not set the variable, so shell-inception detection (which relies on DEVBOX_SHELL_ENABLED) keeps working in every shell. ✅
• Plain devbox shellenv is likewise unaffected.

How was it tested?

• go build ./... and go vet ./internal/devbox/ pass.
• Added a regression testscript testscripts/shell/shellenv_init_hook.test.txt asserting that:
  • devbox shellenv --init-hook exports DEVBOX_SHELL_ENABLED="1", and
  • plain devbox shellenv does not export it.

Note: the nix-backed testscripts could not be executed in the authoring environment (no nix available), but the change is small and the new test documents the expected behavior for CI.

cc @miklschmidt (issue reporter)

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Generated by Claude Code

[Copilot]

Pull request overview

This PR fixes the direnv activation path so that DEVBOX_SHELL_ENABLED is exported when entering a Devbox environment via devbox shellenv --init-hook, aligning behavior with the documented env-var semantics and resolving #2746.

Changes:

• Set DEVBOX_SHELL_ENABLED=1 inside Devbox.EnvExports() when RunHooks is enabled (i.e., shellenv --init-hook), while leaving plain shellenv / global shellenv unchanged.
• Add a regression testscript to assert --init-hook exports the variable and plain shellenv does not.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
internal/devbox/devbox.go	Exports DEVBOX_SHELL_ENABLED when EnvExports is invoked with init hooks enabled (RunHooks=true).
testscripts/shell/shellenv_init_hook.test.txt	Adds coverage to prevent regressions for shellenv --init-hook vs plain shellenv.

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