From 1645e43dabe68cfcec16d2bfc0af3abf9073dc06 Mon Sep 17 00:00:00 2001
From: Claude <noreply@anthropic.com>
Date: Wed, 10 Jun 2026 14:13:25 +0000
Subject: [PATCH] fix(direnv): set DEVBOX_SHELL_ENABLED when entering env via
 shellenv --init-hook

The direnv integration loads the Devbox environment by evaluating
`devbox shellenv --init-hook`, but that path never set
DEVBOX_SHELL_ENABLED. As a result `$DEVBOX_SHELL_ENABLED` was empty in
direnv-activated shells, contradicting the documented behavior that it is
set to 1 whenever the environment is loaded.

Set DEVBOX_SHELL_ENABLED=1 in EnvExports when init hooks are run, mirroring
what Shell() and RunScript() already do. The flag is gated on RunHooks so
that the global integration (`devbox global shellenv`, which does not run
init hooks) does not set it in every shell and break shell-inception
detection.

Adds a regression testscript asserting that `devbox shellenv --init-hook`
exports the variable while plain `devbox shellenv` does not.

Fixes #2746
---
 internal/devbox/devbox.go                     | 12 ++++++++++++
 testscripts/shell/shellenv_init_hook.test.txt | 13 +++++++++++++
 2 files changed, 25 insertions(+)
 create mode 100644 testscripts/shell/shellenv_init_hook.test.txt

diff --git a/internal/devbox/devbox.go b/internal/devbox/devbox.go
index 8ac001233d3..7c5af9161cf 100644
--- a/internal/devbox/devbox.go
+++ b/internal/devbox/devbox.go
@@ -379,6 +379,18 @@ func (d *Devbox) EnvExports(ctx context.Context, opts devopt.EnvExportsOpts) (st
 		return "", err
 	}
 
+	// When we also run the init hooks we are fully entering the Devbox
+	// environment (this is what the direnv integration does via
+	// `devbox shellenv --init-hook`), so mark the shell as Devbox-enabled.
+	// This mirrors Shell() and RunScript(), and matches the documented
+	// behavior that DEVBOX_SHELL_ENABLED is set whenever the environment is
+	// loaded. We intentionally gate this on RunHooks so that the global
+	// integration (`devbox global shellenv`, which does not run init hooks)
+	// does not set it in every shell and break shell-inception detection.
+	if opts.RunHooks {
+		envs[envir.DevboxShellEnabled] = "1"
+	}
+
 	// Use the appropriate export format based on shell type
 	var envStr string
 	if opts.ShellFormat == devopt.ShellFormatNushell {
diff --git a/testscripts/shell/shellenv_init_hook.test.txt b/testscripts/shell/shellenv_init_hook.test.txt
new file mode 100644
index 00000000000..72b92e5acd4
--- /dev/null
+++ b/testscripts/shell/shellenv_init_hook.test.txt
@@ -0,0 +1,13 @@
+exec devbox init
+
+# When run with --init-hook (as the direnv integration does via
+# `devbox shellenv --init-hook`), we are fully entering the Devbox
+# environment, so DEVBOX_SHELL_ENABLED must be exported. See issue #2746.
+exec devbox shellenv --init-hook
+stdout 'export DEVBOX_SHELL_ENABLED="1";'
+
+# Plain shellenv (used by the global integration `devbox global shellenv`,
+# which runs in every shell) must NOT set DEVBOX_SHELL_ENABLED, otherwise
+# shell-inception detection would break in every shell.
+exec devbox shellenv
+! stdout 'DEVBOX_SHELL_ENABLED'