fix: Always display session/container name in isolation output

docs/case-studies/issue-67/ANALYSIS.md

@@ -0,0 +1,159 @@
+# Case Study: Issue #67 - Display Session Name and Container Name When Different from Session UUID
+
+## Overview
+
+**Issue:** When using isolation backends (screen, docker, tmux), the output shows a session UUID but not the actual container/screen/tmux session name that users need to reconnect to the session, especially in detached mode.
+
+**Priority:** Bug / Enhancement / Documentation
+
+## Problem Description
+
+When running commands with isolation (screen, docker, tmux), the tool generates two different identifiers:
+1. **Session UUID** - A unique identifier for tracking executions (e.g., `f1efebcd-5426-437b-92db-b94acaaf421c`)
+2. **Session/Container Name** - The actual name used by the isolation backend (e.g., `docker-1767841051864-c0qs07`)
+
+Currently, only the session UUID is displayed in output blocks, but users need the actual session/container name to:
+- Reconnect to detached sessions (`screen -r <name>`, `tmux attach -t <name>`)
+- View container logs (`docker logs <name>`)
+- Attach to containers (`docker attach <name>`)
+- Kill sessions (`screen -S <name> -X quit`, `docker rm -f <name>`)
+
+## Root Cause Analysis
+
+### Timeline of Code Flow
+
+1. **Session UUID Generation** (`cli.js:234`):
+   ```javascript
+   const sessionId = wrapperOptions.sessionId || generateUUID();
+   ```
+   This generates the tracking UUID, e.g., `f1efebcd-5426-437b-92db-b94acaaf421c`
+
+2. **Session Name Generation** (`cli.js:410-412`):
+   ```javascript
+   const sessionName = options.session ||
+     `${environment || 'start'}-${Date.now()}-${Math.random().toString(36).substring(2, 8)}`;
+   ```
+   This generates the backend session name, e.g., `docker-1767841051864-c0qs07`
+
+3. **Extra Lines for Isolation** (`cli.js:470-485`):
+   Currently only adds:
+   - `[Isolation] Environment: docker, Mode: attached`
+   - `[Isolation] Session: <name>` (only if explicitly provided via --session)
+   - `[Isolation] Image: ubuntu:latest`
+   - `[Isolation] Endpoint: user@host` (for SSH)
+   - `[Isolation] User: <user>` (for user isolation)
+
+4. **Output Block Generation** (`output-blocks.js:181-205`):
+   - Parses extraLines for isolation metadata
+   - Generates spine lines with container/screen/tmux names
+   - But the actual session name is **not passed** when auto-generated
+
+### The Gap
+
+The issue is in `cli.js` - when no explicit `--session` is provided, the auto-generated session name is not added to `extraLines`, so `output-blocks.js` cannot display it.
+
+Currently:
+```javascript
+if (options.session) {
+  extraLines.push(`[Isolation] Session: ${options.session}`);
+}
+```
+
+This only adds the session line when user explicitly provides `--session`, but NOT when it's auto-generated.
+
+## Proposed Solution
+
+### Option 1: Always Add Session Name to extraLines (Recommended)
+
+In `cli.js`, after generating `sessionName`, always add it to extraLines regardless of whether it was explicitly provided:
+
+```javascript
+// Always add the actual session/container name used
+extraLines.push(`[Isolation] Session: ${sessionName}`);
+```
+
+This ensures that `output-blocks.js` can always display the correct session/container/screen name.
+
+### Option 2: Use Session UUID for Session Names
+
+Alternative approach: Try to use the session UUID as the session name when possible. However, this has limitations:
+- UUIDs are long (36 characters) which may exceed name limits
+- Some backends have character restrictions (docker container names must match `[a-zA-Z0-9][a-zA-Z0-9_.-]*`)
+- UUIDs contain dashes which may cause issues in some contexts
+
+### Recommendation
+
+**Implement Option 1** - Always pass the actual session name to extraLines. This is:
+- Minimal code change
+- Backward compatible
+- Provides users with the information they need
+- Allows them to reconnect to detached sessions
+
+## Implementation Steps
+
+### JavaScript Implementation (completed)
+
+1. Modified `js/src/bin/cli.js` to always add `[Isolation] Session: ${sessionName}` to extraLines
+2. Added tests in `js/test/cli.test.js` to verify the session name is displayed for screen, tmux, and docker
+3. Created changeset `js/.changeset/issue-67-display-session-name.md`
+
+### Rust Implementation (completed)
+
+1. Modified `rust/src/bin/main.rs` to always add the session name to extraLines when using isolation
+2. Added tests in `rust/src/lib/output_blocks.rs` to verify the session name is displayed for screen, tmux, and docker
+3. Created changelog fragment `rust/changelog.d/67.md`
+
+## Impact
+
+- **Users** will see the actual session/container name in output, enabling them to:
+  - Reconnect to detached screen sessions
+  - Attach to tmux sessions
+  - View Docker container logs
+  - Remove containers
+- **Backward Compatibility**: No breaking changes - just additional information displayed
+
+## References
+
+- Issue: https://github.com/link-foundation/start/issues/67
+- Related Files:
+  - JavaScript:
+    - `js/src/bin/cli.js` - Main CLI logic
+    - `js/src/lib/output-blocks.js` - Output formatting
+    - `js/src/lib/isolation.js` - Isolation backend runners
+    - `js/src/lib/args-parser.js` - Argument parsing
+    - `js/test/cli.test.js` - Tests for issue #67 fix
+  - Rust:
+    - `rust/src/bin/main.rs` - Main CLI logic
+    - `rust/src/lib/output_blocks.rs` - Output formatting (with tests)
+    - `rust/src/lib/isolation.rs` - Isolation backend runners
+    - `rust/src/lib/args_parser.rs` - Argument parsing
+
+## User-Provided Log Examples
+
+From the issue description:
+```
+$ --isolated screen -- echo 'hi'
+│ session   a39a17a3-1064-480d-b508-80b8bdd3a93f
+│ start     2026-01-08 02:57:28.115
+│
+│ isolation screen
+│ mode      attached
+│
+$ echo hi
+```
+
+The screen session name (e.g., `screen-1767841048115-nch2wk`) is NOT shown, only the UUID.
+
+With the fix, users would see:
+```
+│ session   a39a17a3-1064-480d-b508-80b8bdd3a93f
+│ start     2026-01-08 02:57:28.115
+│
+│ isolation screen
+│ mode      attached
+│ screen    screen-1767841048115-nch2wk
+│
+$ echo hi
+```
+
+This allows users to reconnect with `screen -r screen-1767841048115-nch2wk`.

docs/case-studies/issue-67/issue-comments.json

@@ -0,0 +1 @@
+[]

docs/case-studies/issue-67/issue-data.json

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But if it is not possible we should make sure at start and end blocks we do display that info, so if for example we use detached mode, or attached mode without closing of screen/docker container we should be able to see all the data to reconnect to them.\n\nPlease download all logs and data related about the issue to this repository, make sure we compile that data to `./docs/case-studies/issue-{id}` folder, and use it to do deep case study analysis (also make sure to search online for additional facts and data), in which we will reconstruct timeline/sequence of events, find root causes of the problem, and propose possible solutions.","closed_by":null,"reactions":{"url":"https://api.github.com/repos/link-foundation/start/issues/67/reactions","total_count":0,"+1":0,"-1":0,"laugh":0,"hooray":0,"confused":0,"heart":0,"rocket":0,"eyes":0},"timeline_url":"https://api.github.com/repos/link-foundation/start/issues/67/timeline","performed_via_github_app":null,"state_reason":null}

js/.changeset/issue-67-display-session-name.md

@@ -0,0 +1,14 @@
+---
+'start-command': patch
+---
+
+fix: Always display session/container name in isolation output
+
+When using isolation backends (screen, docker, tmux), the output now shows the actual session/container name that users need to reconnect to sessions, especially in detached mode. Previously, only the session UUID was shown, but users need the actual backend name to:
+
+- Reconnect to detached screen sessions: `screen -r <name>`
+- Attach to tmux sessions: `tmux attach -t <name>`
+- View Docker container logs: `docker logs <name>`
+- Remove containers: `docker rm -f <name>`
+
+Fixes #67

js/src/bin/cli.js

@@ -470,9 +470,10 @@ async function runWithIsolation(
   // Add isolation info to extra lines
   if (environment) {
     extraLines.push(`[Isolation] Environment: ${environment}, Mode: ${mode}`);
-  }
-  if (options.session) {
-    extraLines.push(`[Isolation] Session: ${options.session}`);
+    // Always add the session name so users can reconnect to detached sessions
+    // This is important for screen, tmux, docker where the session/container name
+    // is different from the session UUID used for tracking (see issue #67)
+    extraLines.push(`[Isolation] Session: ${sessionName}`);
   }
   if (effectiveImage) {
     extraLines.push(`[Isolation] Image: ${effectiveImage}`);

js/test/cli.test.js

@@ -122,3 +122,97 @@ describe('CLI basic behavior', () => {
     assert.ok(result.stdout.includes('Usage:'), 'Should display usage');
   });
 });
+
+describe('CLI isolation output (issue #67)', () => {
+  const { isCommandAvailable } = require('../src/lib/isolation');
+
+  it('should display screen session name when using screen isolation', async () => {
+    if (!isCommandAvailable('screen')) {
+      console.log('  Skipping: screen not installed');
+      return;
+    }
+
+    const result = runCLI(['-i', 'screen', '--', 'echo', 'hello']);
+
+    // The output should contain the screen session name (in format screen-timestamp-random)
+    // Check that the session UUID is displayed
+    assert.ok(
+      result.stdout.includes('│ session'),
+      'Should display session UUID'
+    );
+    // Check that screen isolation info is displayed
+    assert.ok(
+      result.stdout.includes('│ isolation screen'),
+      'Should display screen isolation'
+    );
+    // Check that the actual screen session name is displayed (issue #67 fix)
+    assert.ok(
+      result.stdout.includes('│ screen    screen-'),
+      'Should display actual screen session name for reconnection (issue #67)'
+    );
+  });
+
+  it('should display tmux session name when using tmux isolation', async () => {
+    if (!isCommandAvailable('tmux')) {
+      console.log('  Skipping: tmux not installed');
+      return;
+    }
+
+    const result = runCLI(['-i', 'tmux', '--', 'echo', 'hello']);
+
+    // The output should contain the tmux session name
+    assert.ok(
+      result.stdout.includes('│ session'),
+      'Should display session UUID'
+    );
+    assert.ok(
+      result.stdout.includes('│ isolation tmux'),
+      'Should display tmux isolation'
+    );
+    // Check that the actual tmux session name is displayed (issue #67 fix)
+    assert.ok(
+      result.stdout.includes('│ tmux      tmux-'),
+      'Should display actual tmux session name for reconnection (issue #67)'
+    );
+  });
+
+  it('should display docker container name when using docker isolation', async () => {
+    const { canRunLinuxDockerImages } = require('../src/lib/isolation');
+
+    if (!canRunLinuxDockerImages()) {
+      console.log(
+        '  Skipping: docker not available or cannot run Linux images'
+      );
+      return;
+    }
+
+    const result = runCLI([
+      '-i',
+      'docker',
+      '--image',
+      'alpine:latest',
+      '--',
+      'echo',
+      'hello',
+    ]);
+
+    // The output should contain the docker container name
+    assert.ok(
+      result.stdout.includes('│ session'),
+      'Should display session UUID'
+    );
+    assert.ok(
+      result.stdout.includes('│ isolation docker'),
+      'Should display docker isolation'
+    );
+    assert.ok(
+      result.stdout.includes('│ image     alpine:latest'),
+      'Should display docker image'
+    );
+    // Check that the actual container name is displayed (issue #67 fix)
+    assert.ok(
+      result.stdout.includes('│ container docker-'),
+      'Should display actual container name for reconnection (issue #67)'
+    );
+  });
+});

rust/changelog.d/67.md

@@ -0,0 +1,13 @@
+fix: Always display session/container name in isolation output
+
+When using isolation backends (screen, docker, tmux), the output now always displays
+the actual session/container name that users need to reconnect to sessions. Previously,
+the session name was only shown if explicitly provided via `--session` flag.
+
+This allows users to:
+- Reconnect to detached screen sessions: `screen -r <name>`
+- Attach to tmux sessions: `tmux attach -t <name>`
+- View Docker container logs: `docker logs <name>`
+- Remove containers: `docker rm -f <name>`
+
+Fixes #67

rust/src/bin/main.rs

@@ -507,9 +507,10 @@ fn run_with_isolation(
     // Add isolation info to extra lines
     if let Some(env) = environment {
         extra_lines.push(format!("[Isolation] Environment: {}, Mode: {}", env, mode));
-    }
-    if let Some(ref session) = wrapper_options.session {
-        extra_lines.push(format!("[Isolation] Session: {}", session));
+        // Always add the session name so users can reconnect to detached sessions
+        // This is important for screen, tmux, docker where the session/container name
+        // is different from the session UUID used for tracking (see issue #67)
+        extra_lines.push(format!("[Isolation] Session: {}", session_name));
     }
     if let Some(ref image) = effective_image {
         extra_lines.push(format!("[Isolation] Image: {}", image));