Two bugs caught in supervisor review:
1. Stderr was silently dropped when the Details panel was closed during a
crash. _on_spawn_done appended to diag_text only when the panel was
already open, and refresh_dependency() clobbered that text on the next
field change anyway.
Fix: stash the result in self._last_spawn; _full_diag_text() appends
the stderr section whenever diag text is generated; _on_spawn_done
auto-opens the panel on non-ok outcomes (same pattern as the existing
auto_open for missing commands).
2. _drain stopped reading once _STDERR_CAP (4 KB) was reached. A process
that writes more than 4 KB then blocked on a full pipe buffer, never
exited, and was misclassified as "ok" instead of "crashed".
Fix: drain to EOF unconditionally; keep only the first _STDERR_CAP bytes.
Regression test: 64 KB stderr + exit(3) → outcome "crashed".
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Add spawn_test() to bcc_core — spawns a stdio server for up to 3 s,
captures stderr, and reports ok/exited/crashed/not_found. Key design
decisions driven by real MCP server behaviour:
- stdin=PIPE (never written): servers block on JSON-RPC input and stay
alive, so "still running after timeout" reliably signals a healthy
start. stdin=DEVNULL would send EOF, causing well-behaved servers to
exit 0 and be misclassified as "exited".
- Command resolved via shutil.which(augmented_path()) before Popen so
subprocess PATH resolution is unambiguous across platforms.
- start_new_session=True on POSIX + os.killpg on timeout: kills the
whole process group, not just the launcher (npx, uvx), which would
otherwise orphan the actual node/python grandchild process.
- stdout=DEVNULL: draining a PIPE we don't read would deadlock at ~64 KB.
- stderr drained in a daemon thread, capped at 4 KB.
GUI: SpawnTester(QThread) wraps spawn_test; "Test launch" button in
ServerEditor dep row (stdio only, visible when command resolves ok/warn).
Result colours match the existing dep-status palette (green/amber/red).
Stderr appended to the diagnostics panel if it is open.
7 new unit tests cover all outcomes and the stdin-open regression guard.
Ran python bcc.py locally: button appears for stdio servers whose command
resolves, is hidden for remote servers and missing-command servers.
Closes#2
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
- Env/header values whose key looks secret (TOKEN, API_KEY, PASSWORD,
AUTH, ...) render as •••••••• via a display-only delegate; a
'Show secrets' toggle reveals them. Underlying data, editing, and
save are untouched.
- The Add dialog switches the value field to password echo when the
key name looks secret.
- Copy-diagnostics now redacts secrets from args (--token <v>,
--api-key=<v>, and well-known token prefixes like ghp_/sk-/xoxb-),
since those reports get pasted into public bug reports. Env and
header values were already omitted from diagnostics.
Claude Code stores user-scope MCP servers in ~/.claude.json (what
'claude mcp add' writes); ~/.claude/settings.json is for permissions
and hooks and rejects an mcpServers key with a schema error, so BCC
was reading (and writing) servers where Claude Code never looks.
If servers are found parked in settings.json, that file is still
listed as 'Claude Code (legacy settings.json)' so they can be copied
into the real config via Copy to. Docs updated; verified against
docs.claude.com/en/docs/claude-code/settings.
AJ