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#1545 · Spawned agent shells inherit _VOLTA_TOOL_RECURSION, breaking bare node/npm/npx

Bug Low Effort: Low host open on GitHub 2026-08-18 base 16ceb3a540f81c1189efaffb27a39b1d9443abf5 (main)

Verdict: REPRODUCED · root-cause confidence: high · linked open PRs: none

TL;DR

Plain-language framing. Volta is a Node version manager. It installs tiny "shim" programs named node, npm, npx into ~/.volta/bin; when you run node, the shim looks up which Node version applies and executes the real binary. To avoid infinite loops when a shim ends up calling another shim, Volta sets an environment variable _VOLTA_TOOL_RECURSION=1 on every program it launches; a shim that sees this variable skips the version lookup and simply passes through to whatever node is on the system PATH (with Volta's own directories removed). If bb itself was installed with Volta (volta install bb-app), the bb command the user types is such a shim, so the whole bb process tree, server and host daemon, is born with _VOLTA_TOOL_RECURSION=1.

The host daemon spawns every agent provider (Claude Code, Codex, ...) and every integrated terminal with its own environment minus BB_*/NODE_ENV, and with PATH replaced by the user's login-shell PATH (which puts ~/.volta/bin, the shims, back in front). Nothing strips _VOLTA_TOOL_RECURSION. So when the agent runs node --version in its shell tool, Volta's shim sees the guard, refuses to resolve the default Node, and, on a machine that has no Node outside Volta, fails with the misleading Volta error: Node is not available. Because bb's own $BB_CLI entry (host-daemon/dist/bb) is a #!/usr/bin/env node script and bb prepends its directory to PATH, bb and $BB_CLI fail in the agent shell for the same reason.

I reproduced this end to end on Linux with a scratch Volta 2.0.2 install, a real Claude Code turn, and a control run (guard unset: v24.19.0). I verified every code claim in the issue against Volta v2.0.2 source and against bb's spawn paths. Nothing on origin/main after the base commit touches this. A one-hunk fix in sanitizeInheritedChildProcessEnv, the single choke point for bb child environments, makes the failing repro test pass and makes the same agent turn succeed while the daemon still carries the guard.

Claims vs findings

Environment

• bb 16ceb3a540f81c1189efaffb27a39b1d9443abf5 (main, 2026-08-18), worktree /home/sawyer/projects/bb/.claude/worktrees/wf_242c3e11-a10-44. Dev instance: app :12582, server :20582, host daemon :28582, data dir /home/sawyer/.bb-dev/projects-bb-.claude-worktrees-wf_242c3e11-a10-44-f277ec6ef1d9. Host host_kk7mydvk3d, project proj_df22yte62v (local path /tmp/bb-1545-qa-repo).
• Linux 7.0.0-29-generic x86_64. Node v24.18.0 (nvm) runs bb itself. Volta 2.0.2 installed into scratch VOLTA_HOME=/tmp/bb-1545-volta with node@24.19.0 as default. Provider: claude-code (Claude Code CLI 2.1.234, standalone binary at ~/.local/bin/claude, model claude-opus-5[1m]).
• Threads: thr_qye8969p6r (guard set → fails), thr_3hw49iun4j (guard unset → works), thr_hj9rx8rcb7 (guard set + proposed fix → works).
• Screenshots via dev-browser --headless (Playwright Chromium 1208).

Minimal reproduction

Two ingredients are needed on the machine: (a) Volta with a default Node and (b) no other Node on the PATH the agent shell gets. Neither exists on this box, so I install Volta into a scratch directory and use a wrapper login shell so the daemon's PATH probe yields "Volta shims first, no other Node". The one thing being simulated is how the guard gets into bb-app's environment: instead of running bb-app through a real Volta package shim I export _VOLTA_TOOL_RECURSION=1 before starting the dev instance. Appendix A shows a real Volta package shim sets exactly that variable. All helper files are in 1545/repro/.

1. Install Volta 2.0.2 + Node into a scratch home and confirm the Volta mechanism in isolation:

   $ export VOLTA_HOME=/tmp/bb-1545-volta
   $ curl -sSf https://get.volta.sh | bash -s -- --skip-setup
   $ export PATH=$VOLTA_HOME/bin:/usr/local/bin:/usr/bin:/bin     # no other node on this PATH
   $ volta install node@24
   $ volta list | head -1
   runtime node@24.19.0 (default)
   $ node --version
   v24.19.0
   $ _VOLTA_TOOL_RECURSION=1 node --version
   Volta error: Node is not available.
   
   To run any Node command, first set a default version using `volta install node`
   Error details written to /tmp/bb-1545-volta/log/volta-error-2026-08-18_08_08_46.984.log
   exit=126

2. Create the wrapper login shell (1545/repro/fake-login-shell). The daemon runs $SHELL -ilc env at startup and hands the resulting PATH to agent shells; this wrapper stands in for a user whose login PATH has ~/.volta/bin and no other Node:

   #!/bin/bash
   # Repro helper for get-bb/bb#1545.
   # Simulates a user whose login shell puts Volta's shim directory on PATH and
   # who has NO Node install outside Volta (the issue's environment). The host
   # daemon probes `$SHELL -ilc env` to derive the PATH it hands to agent shells.
   export VOLTA_HOME=/tmp/bb-1545-volta
   export PATH=/tmp/bb-1545-volta/bin:/home/sawyer/.local/bin:/usr/local/bin:/usr/bin:/bin
   exec /bin/bash --noprofile --norc "$@"
   

3. Build and start your dev instance with the guard in its environment, exactly as a Volta-launched bb-app would have it (from the worktree root):

   $ pnpm install --frozen-lockfile --prefer-offline && pnpm exec turbo run build
   $ export _VOLTA_TOOL_RECURSION=1 VOLTA_HOME=/tmp/bb-1545-volta SHELL=/tmp/bb-1545-volta/fake-login-shell
   $ scripts/bb-dev-app current
   ...
   Server: http://localhost:20582
   Host daemon: http://127.0.0.1:28582
   $ /tmp/bb-reports/issues/1545/repro/check-daemon-env.sh | grep -A3 'host-daemon/src/index.ts'
   pid 2811282: /home/sawyer/.nvm/versions/node/v24.18.0/bin/node --conditions=source --import tsx apps/host-daemon/src/index.ts
   VOLTA_HOME=/tmp/bb-1545-volta
   _VOLTA_TOOL_RECURSION=1
   SHELL=/tmp/bb-1545-volta/fake-login-shell

4. Create a scratch repo + project and spawn a Claude Code thread that runs node --version:

   $ /tmp/bb-reports/issues/1545/repro/make-qa-repo.sh
   $ export BB_SERVER_URL=http://localhost:20582 BB_HOST_DAEMON_PORT=28582
   $ curl -s -X POST $BB_SERVER_URL/api/v1/projects -H 'content-type: application/json' \
       -d '{"name":"qa","source":{"type":"local_path","path":"/tmp/bb-1545-qa-repo","hostId":"host_kk7mydvk3d"}}'
   {"id":"proj_df22yte62v", ...}
   $ node packages/scripts/dist/commands/run-cli.js thread spawn --project proj_df22yte62v --provider claude-code \
       --permission-mode full --title "1545 volta repro" \
       --prompt "Run exactly this shell command with your bash tool: node --version; echo exit=\$?; echo VOLTA=\$_VOLTA_TOOL_RECURSION. Then reply with ONLY the verbatim combined stdout+stderr of that command, nothing else." --json
   $ node packages/scripts/dist/commands/run-cli.js thread log thr_qye8969p6r

   Expected: v24.19.0 (Volta is healthy; the user's own shell prints that). Actual (full log, json with the commandExecution item):

   ── User ────────────────────────────────────────────────────
   Run exactly this shell command with your bash tool: node --version; echo exit=$?; echo VOLTA=$_VOLTA_TOOL_RECURSION. Then reply with ONLY the verbatim combined stdout+stderr of that command, nothing else.
   
   ── Provisioned thread ──────────────────────────────────────
     Preparing workspace
     Using workspace: /tmp/bb-1545-qa-repo
     Using branch: main (8a9e7fc)
   
   ── Worked for (2s) ─────────────────────────────────────────
   
   ── Assistant ───────────────────────────────────────────────
   Volta error: Node is not available.
   
   To run any Node command, first set a default version using `volta install node`
   Error details written to /tmp/bb-1545-volta/log/volta-error-2026-08-18_08_12_51.828.log
   exit=126
   VOLTA=1
   

   Volta's own error log for that call (saved) shows it is a pass-through failure, not a resolution failure:

   "node" "--version"
   Volta v2.0.2
   
   Node is not available.
   
   To run any Node command, first set a default version using `volta install node`
   
   Error cause: No such file or directory (os error 2)
   

   

5. Control: stop, restart without the guard (same wrapper shell, same scratch Volta), same prompt (log):

   $ pnpm dev:stop; unset _VOLTA_TOOL_RECURSION; scripts/bb-dev-app current
   $ node packages/scripts/dist/commands/run-cli.js thread spawn ... (same prompt) --json   # thr_3hw49iun4j
   $ node packages/scripts/dist/commands/run-cli.js thread log thr_3hw49iun4j | tail -4
   ── Assistant ───────────────────────────────────────────────
   v24.19.0
   exit=0
   VOLTA=

6. The $BB_CLI/bb consequence, using the exact env shape the daemon gives agent shells (PATH=<dist>:<login PATH>, BB_CLI=<dist>/bb), script 1545/repro/bb-cli-in-agent-shell.sh:

   $ head -1 /home/sawyer/projects/bb/.claude/worktrees/wf_242c3e11-a10-44/apps/host-daemon/dist/bb
   #!/usr/bin/env node
   exit=0
   
   $ node --version
   Volta error: Node is not available.
   
   To run any Node command, first set a default version using `volta install node`
   Error details written to /tmp/bb-1545-volta/log/volta-error-2026-08-18_08_15_27.941.log
   exit=126
   
   $ /home/sawyer/projects/bb/.claude/worktrees/wf_242c3e11-a10-44/apps/host-daemon/dist/bb --version
   Volta error: Node is not available.
   
   To run any Node command, first set a default version using `volta install node`
   Error details written to /tmp/bb-1545-volta/log/volta-error-2026-08-18_08_15_27.979.log
   exit=126
   
   $ bb --version
   Volta error: Node is not available.
   
   To run any Node command, first set a default version using `volta install node`
   Error details written to /tmp/bb-1545-volta/log/volta-error-2026-08-18_08_15_28.020.log
   exit=126
   
   $ env -u _VOLTA_TOOL_RECURSION bb --version
   0.38.0
   exit=0
   
   

7. Unit-level repro (fails on main, passes with the fix), file 1545/repro/volta-recursion-guard.repro.test.ts, place it at packages/process-utils/test/ and run pnpm exec vitest run test/volta-recursion-guard.repro.test.ts from packages/process-utils:

   // Repro for get-bb/bb#1545: agent shells inherit Volta's `_VOLTA_TOOL_RECURSION`
   // re-entrancy guard from a Volta-launched bb-app, which makes Volta's `node`,
   // `npm`, and `npx` shims skip platform resolution and fail with
   // "Volta error: Node is not available." on machines whose only Node is Volta's.
   //
   // `sanitizeInheritedChildProcessEnv` is the single choke point every
   // bb-spawned child (provider bridges, terminals, git, script automations)
   // goes through, so it is the right place to drop the guard. This test FAILS on
   // 16ceb3a54 because the function only strips `BB_*` and `NODE_ENV`.
   import { describe, expect, it } from "vitest";
   import { sanitizeInheritedChildProcessEnv } from "../src/index.js";
   
   describe("sanitizeInheritedChildProcessEnv (issue #1545)", () => {
     it("does not leak Volta's _VOLTA_TOOL_RECURSION guard into child processes", () => {
       // Exactly what a Volta package shim injects into bb-app's process env
       // (verified with a probe package installed through `npm i -g` under Volta).
       const env: NodeJS.ProcessEnv = {
         HOME: "/Users/example",
         PATH: "/Users/example/.volta/tools/image/node/25.0.0/bin:/Users/example/.volta/bin:/usr/bin:/bin",
         VOLTA_HOME: "/Users/example/.volta",
         _VOLTA_TOOL_RECURSION: "1",
       };
   
       const sanitizedEnv = sanitizeInheritedChildProcessEnv({
         env,
         // The daemon substitutes the user's login-shell PATH, which puts Volta's
         // shim directory (not the image bin dir) in front.
         shellPath: "/Users/example/.volta/bin:/usr/bin:/bin",
       });
   
       // VOLTA_HOME must survive: the shims need it to find the Volta layout.
       expect(sanitizedEnv.VOLTA_HOME).toBe("/Users/example/.volta");
       expect(sanitizedEnv.PATH).toBe("/Users/example/.volta/bin:/usr/bin:/bin");
       // This is the assertion that fails on main: the guard is passed through,
       // so `node` in the child resolves to Volta's shim, which sees the guard,
       // skips `Platform::current`, and returns `ErrorKind::NoPlatform`.
       expect("_VOLTA_TOOL_RECURSION" in sanitizedEnv).toBe(false);
     });
   });
   

   Output on 16ceb3a54 (log):

    RUN  v4.1.1 /home/sawyer/projects/bb/.claude/worktrees/wf_242c3e11-a10-44/packages/process-utils
   
    ❯  @bb/process-utils  test/volta-recursion-guard.repro.test.ts (1 test | 1 failed) 6ms
        × does not leak Volta's _VOLTA_TOOL_RECURSION guard into child processes 5ms
   
   ⎯⎯⎯⎯⎯⎯⎯ Failed Tests 1 ⎯⎯⎯⎯⎯⎯⎯
   
    FAIL   @bb/process-utils  test/volta-recursion-guard.repro.test.ts > sanitizeInheritedChildProcessEnv (issue #1545) > does not leak Volta's _VOLTA_TOOL_RECURSION guard into child processes
   AssertionError: expected true to be false // Object.is equality
   
   - Expected
   + Received
   
   - false
   + true
   
    ❯ test/volta-recursion-guard.repro.test.ts:37:53
        35|     // so `node` in the child resolves to Volta's shim, which sees the…
        36|     // skips `Platform::current`, and returns `ErrorKind::NoPlatform`.
        37|     expect("_VOLTA_TOOL_RECURSION" in sanitizedEnv).toBe(false);
          |                                                     ^
        38|   });
        39| });
   
   ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯[1/1]⎯
   
   
    Test Files  1 failed (1)
         Tests  1 failed (1)
      Start at  08:16:48
      Duration  171ms (transform 42ms, setup 0ms, import 61ms, tests 6ms, environment 0ms)
   
   

Root cause

Three facts chain together; the first is Volta's, the second and third are bb's.

1. Volta marks every process it launches. ToolCommand::execute in Volta v2.0.2 sets _VOLTA_TOOL_RECURSION=1 for node, npm, npx, and package binaries alike (executor.rs line 194: self.command.env(RECURSION_ENV_VAR, "1")). The runtime shims interpret it as "do not re-evaluate the platform" (node.rs lines 13-17) and, with platform = None, exec through System::path(), the PATH with Volta directories removed, reporting ErrorKind::NoPlatform ("Node is not available") if that fails. Volta itself removes the variable before volta run because a new command is a new context (mod.rs lines 58-60).
2. bb forwards the whole inherited environment. bb-app builds the daemon env from its own process.env (packages/bb-app/src/launcher.ts:2457, via stripThreadContextEnv, which only removes thread-context BB_*). The daemon then builds every child env with sanitizeInheritedChildProcessEnv, whose documented contract is "the parent's env minus BB_* and NODE_ENV":

   export function sanitizeInheritedChildProcessEnv(
     args: SanitizeInheritedChildProcessEnvArgs,
   ): NodeJS.ProcessEnv {
     const sanitizedEnv: NodeJS.ProcessEnv = {};
     for (const [key, value] of Object.entries(args.env)) {
       if (value === undefined) {
         continue;
       }
       if (key === "NODE_ENV" || key.startsWith("BB_")) {
         continue;
       }
       sanitizedEnv[key] = value;
     }
     if (args.shellPath !== undefined) {
       sanitizedEnv.PATH = args.shellPath;
     }
     return sanitizedEnv;
   }

   (packages/process-utils/src/index.ts:188). Consumers: provider bridge processes (packages/agent-runtime/src/runtime-provider-process.ts:494), integrated terminals (apps/host-daemon/src/terminals/terminal-manager.ts:345), git/host-workspace helpers, plugin hosts, and server-side script automations. The provider bridge (Claude Code SDK, Codex app-server, ACP agents) inherits that env and its shell tool inherits it again, so _VOLTA_TOOL_RECURSION=1 arrives intact in the agent's bash, exactly what the thread printed (VOLTA=1).
3. bb swaps PATH for the login-shell PATH, which re-exposes the shims. Volta launched bb-app with PATH=…/.volta/tools/image/node/<v>/bin:…/.volta/bin:… (real binary first; Appendix A), so inside bb-app's own process the guard is harmless. But the daemon computes the agent-shell PATH from $SHELL -ilc env (apps/host-daemon/src/start-host-daemon.ts:239 → apps/host-daemon/src/runtime-shell-env.ts:361), which yields the user's normal ~/.volta/bin-first PATH. Now node is the shim again, the shim sees the leaked guard, and on a machine with no other Node the pass-through has nowhere to go. That is why the reporter's PATH=~/.volta/tools/image/node/25.0.0/bin:$PATH node --version works with the guard still set.

Why the symptom follows. Every node, npm, npx invocation and every #!/usr/bin/env node script in the agent shell hits the shim. bb's own CLI entry host-daemon/dist/bb is such a script and bb puts its directory first on PATH and in BB_CLI, so the agent cannot reach the bb CLI by bb, $BB_CLI, or the absolute path; only the Volta package shim ~/.volta/bin/bb (which uses the platform pinned at install time) still works, but bb's PATH ordering hides it behind the dist copy.

Deeper / adjacent issue. This is a specific instance of a general property: bb children inherit whatever the launcher happened to have, and only bb's own variables are scrubbed. Any tool that stamps a re-entrancy or "already inside me" marker onto its children (Volta is the one that matters in practice; e.g. npm_config_*/npm_lifecycle_event when bb is started from an npm script, or VOLTA_BYPASS) will leak into agent shells the same way. The fix below handles the concrete, verified case; the general problem is worth a comment in sanitizeInheritedChildProcessEnv so future "leaked marker" reports go to the same place. Separately, note that the guard also reaches integrated terminals and server-side script automations (same sanitizer), so the user-visible surface is wider than the issue title says.

Proposed fix (first principles)

Drop _VOLTA_TOOL_RECURSION in sanitizeInheritedChildProcessEnv. It is the single function every bb-spawned child goes through (providers, terminals, git, plugin hosts, automations, native folder picker), it already owns the "what does a child inherit" policy, and it lives in @bb/process-utils which both server and daemon consume, so no server/daemon boundary moves and no wire shape changes (no HOST_DAEMON_PROTOCOL_VERSION bump). This mirrors Volta's own volta run behaviour: a bb child is a new context, so the guard must not carry over. Diff (1545/repro/proposed-fix.diff):

diff --git a/packages/process-utils/src/index.ts b/packages/process-utils/src/index.ts
index 8b8568b47..ce07ccaf0 100644
--- a/packages/process-utils/src/index.ts
+++ b/packages/process-utils/src/index.ts
@@ -177,6 +177,8 @@ export function resolveContainedPath(
   return resolvedCandidatePath;
 }
 
+const VOLTA_RECURSION_GUARD_ENV = "_VOLTA_TOOL_RECURSION";
+
 /**
  * The one answer to "what does a bb-spawned child process inherit": the
  * parent's env minus bb runtime-owned variables (`BB_*`) and `NODE_ENV`,
@@ -194,6 +196,14 @@ export function sanitizeInheritedChildProcessEnv(
     if (key === "NODE_ENV" || key.startsWith("BB_")) {
       continue;
     }
+    // Volta's re-entrancy guard. A Volta package shim sets it on the process
+    // it launches (bb-app), and Volta's own `node`/`npm`/`npx` shims treat its
+    // presence as "do not re-evaluate the platform" and pass through to a
+    // system Node instead. bb children are new contexts, exactly like
+    // `volta run`, which removes the same variable before spawning.
+    if (key === VOLTA_RECURSION_GUARD_ENV) {
+      continue;
+    }
     sanitizedEnv[key] = value;
   }
   if (args.shellPath !== undefined) {

Verification I ran with this patch applied: the repro test and the existing process-utils suite pass (log), and, more importantly, the same Claude Code prompt on a daemon that still carries _VOLTA_TOOL_RECURSION=1 now succeeds (thread thr_hj9rx8rcb7, log):

── User ────────────────────────────────────────────────────
Run exactly this shell command with your bash tool: node --version; echo exit=$?; echo VOLTA=$_VOLTA_TOOL_RECURSION. Then reply with ONLY the verbatim combined stdout+stderr of that command, nothing else.

── Worked for (1s) ─────────────────────────────────────────

── Assistant ───────────────────────────────────────────────
v24.19.0
exit=0
VOLTA=

What could go wrong. (1) The only legitimate use of the guard is Volta's own shim-to-shim recursion within one exec chain; bb never sits inside such a chain, so removing it cannot cause a Volta loop (Volta re-sets it on every tool it launches anyway). (2) Volta launched bb-app with the image bin dir first on PATH; that PATH is already discarded for agent shells today, so behaviour there is unchanged, and for children that keep the inherited PATH (git, plugin hosts) the real node binary is still first, so the shim is never consulted. (3) A dev running bb from a Volta-managed checkout would see child node resolve through Volta's normal project/default pinning instead of pass-through, which is the expected user-shell behaviour. Optional hardening: also drop the variable in bb-app's createDaemonEnv/createServerEnv so the daemon's own process.env is clean (covers any spawn path that bypasses the sanitizer, e.g. code that passes process.env straight through), but the sanitizer change alone fixes every path I could find. No CLI flag, env knob or docs surface is added, so no guide/skill update is required.

PR review

No open PRs are linked to this issue (searched PRs for "volta": none).

Related issues

• #1366 Agent-launched Desktop inherits parent thread storage root (closed): same family, inherited environment leaking into a spawned bb surface; fixed by scrubbing specific BB_* keys in stripThreadContextEnv.
• #1529 Persistent shell session wedges when its cwd is deleted (open): unrelated mechanism, but the same agent-shell surface.
• Upstream precedent: volta-cli/volta run/mod.rs L57-60 removes the same variable before volta run.

Appendix

A. A real Volta package shim sets the guard (and what PATH it hands out)

$ mkdir -p /tmp/bb-1545-envprobe/bin && cd /tmp/bb-1545-envprobe
$ printf '{"name":"bb1545-envprobe","version":"1.0.0","bin":{"bb1545-envprobe":"bin/probe.js"}}' > package.json
$ printf '#!/usr/bin/env node\nconsole.log("_VOLTA_TOOL_RECURSION=" + process.env._VOLTA_TOOL_RECURSION);\nconsole.log("PATH=" + process.env.PATH);\n' > bin/probe.js
$ export VOLTA_HOME=/tmp/bb-1545-volta PATH=/tmp/bb-1545-volta/bin:/usr/local/bin:/usr/bin:/bin
$ npm pack --silent && npm i -g ./bb1545-envprobe-1.0.0.tgz     # Volta intercepts `npm i -g` and creates a package shim
$ ls $VOLTA_HOME/bin
bb1545-envprobe  node  npm  npx  pnpm  volta  volta-migrate  volta-shim  yarn  yarnpkg
$ bb1545-envprobe
_VOLTA_TOOL_RECURSION=1
PATH=/tmp/bb-1545-volta/tools/image/node/24.19.0/bin:/tmp/bb-1545-volta/bin:/usr/local/bin:/usr/bin:/bin

This is the environment bb-app (and therefore the daemon) starts with when installed via Volta. Note the real Node bin dir is first; the daemon's login-shell PATH substitution is what puts the shim back in front for agent shells.

B. Volta v2.0.2 sources consulted (saved copies)

• crates/volta-core/src/run/mod.rs: RECURSION_ENV_VAR, removal before volta run.
• crates/volta-core/src/run/executor.rs: ToolCommand::execute sets the guard for every tool kind.
• crates/volta-core/src/run/node.rs: guard → platform = None → System::path() + NoPlatform.
• crates/volta-core/src/run/binary.rs: package binaries use the platform saved in bin config.

C. Test output with the fix applied

 RUN  v4.1.1 /home/sawyer/projects/bb/.claude/worktrees/wf_242c3e11-a10-44/packages/process-utils


 Test Files  2 passed (2)
      Tests  13 passed (13)
   Start at  08:17:06
   Duration  203ms (transform 63ms, setup 0ms, import 98ms, tests 60ms, environment 0ms)

D. bb code paths that carry the environment (base commit)

• packages/bb-app/src/launcher.ts:2457 createDaemonEnv: daemon env = launcher env minus thread-context BB_*, plus daemon BB_*.
• packages/bb-app/src/launcher.ts:2932 daemon spawned with process.execPath and that env.
• packages/process-utils/src/index.ts:188 sanitizeInheritedChildProcessEnv: strips only BB_*, NODE_ENV.
• apps/host-daemon/src/start-host-daemon.ts:239 agent-shell PATH from resolveUserShellPath().
• apps/host-daemon/src/runtime-shell-env.ts:361 prepareRuntimeShellEnv: prepends dist dir, sets BB_CLI.
• packages/agent-runtime/src/runtime-provider-process.ts:494 provider process env; apps/host-daemon/src/terminals/terminal-manager.ts:345 terminal env.

E. Commands run (chronological, abridged)

gh issue view 1545 --comments
pnpm install --frozen-lockfile --prefer-offline ; pnpm exec turbo run build
curl -sSf https://get.volta.sh | VOLTA_HOME=/tmp/bb-1545-volta bash -s -- --skip-setup ; volta install node@24
_VOLTA_TOOL_RECURSION=1 node --version                                   # Volta mechanism in isolation
git checkout 16ceb3a54 ; pnpm install ; pnpm exec turbo run build        # worktree had drifted to a108fa7ef; pinned to base
export _VOLTA_TOOL_RECURSION=1 VOLTA_HOME=... SHELL=.../fake-login-shell ; scripts/bb-dev-app current
1545/repro/check-daemon-env.sh                                            # daemon has the guard
1545/repro/make-qa-repo.sh ; curl POST /api/v1/projects ; bb thread spawn (claude-code) ; bb thread log   # thr_qye8969p6r FAILS
pnpm dev:stop ; unset _VOLTA_TOOL_RECURSION ; scripts/bb-dev-app current ; bb thread spawn ...            # thr_3hw49iun4j OK (control)
1545/repro/bb-cli-in-agent-shell.sh apps/host-daemon/dist                # $BB_CLI / bb fail, env -u works
npm i -g ./bb1545-envprobe-1.0.0.tgz under Volta ; bb1545-envprobe        # real package shim sets guard
vitest run test/volta-recursion-guard.repro.test.ts                       # FAILS on main
apply proposed-fix.diff ; vitest run                                      # passes
pnpm dev:stop ; export _VOLTA_TOOL_RECURSION=1 ... ; scripts/bb-dev-app current ; bb thread spawn ...     # thr_hj9rx8rcb7 OK with fix
dev-browser --headless run 1545/repro/browser-screenshots.js
git fetch origin main ; git log 16ceb3a54..origin/main -- <relevant paths>   # empty: not fixed upstream
pnpm dev:stop