Update Pylance version to 2026.2.1 and add chat customization guidelines

.claude/skills/glass-tests/SKILL.md

@@ -0,0 +1,79 @@
+---
+name: glass-tests
+description: "Use when working with PTVS Glass tests: setup_glass.py, run_glass.py, Glass.TestAdapter, Newtonsoft.Json assembly mismatches, Azure Pipelines Glass cache, TestScript.xml, glass2.exe, and mixed-mode Python debugger tests."
+argument-hint: "[setup|run|ci-failure|debug]"
+---
+
+# PTVS Glass Tests
+
+## When to Use
+
+Use this skill when setting up, running, debugging, or investigating CI failures for PTVS Glass tests. Glass tests exercise Visual Studio debugger behavior, including mixed-mode Python/native scenarios, and require Microsoft-internal drops for the Glass runner.
+
+Link to existing human-facing documentation instead of duplicating it. Start with [Python/Tests/GlassTests/readme.txt](../../../Python/Tests/GlassTests/readme.txt), which links the internal Concord Glass docs and presentation.
+
+## Key Files
+
+- [Build/setup_glass.py](../../../Build/setup_glass.py): downloads `drop.exe`, Glass, NuGet tools, and vstest drops; extracts VSIX payloads; copies PTVS debugger bits; discovers installed Python versions; generates `.GlassTestProps` files; verifies the test listing.
+- [Build/run_glass.py](../../../Build/run_glass.py): calls `copy_ptvs_output()`, verifies the runtime test root, and invokes `vstest.console.exe` with `/Parallel` and TRX logging.
+- [Build/templates/run_tests.yml](../../../Build/templates/run_tests.yml): installs Python versions, restores or populates the `GlassTests` cache, acquires the Azure DevOps token, runs setup, runs tests, and publishes TRX results.
+- [Python/Tests/GlassTests/PythonTests/PythonConcord.GlassTestRoot](../../../Python/Tests/GlassTests/PythonTests/PythonConcord.GlassTestRoot): root Glass test configuration.
+- `Python/Tests/GlassTests/PythonTests/**/TestScript.xml`: individual debugger test scripts with commands, expected events, breakpoints, and source expectations.
+- `GlassTests/`: generated/runtime directory for downloaded Glass bits and copied tests; do not treat it as the source of truth for test definitions.
+
+## Local Workflow
+
+1. Build PTVS first so the chosen build output contains `EnvironmentDiscover.exe`, `Microsoft.Python*`, and `DkmDebu*` files.
+2. Prefer passing the build output explicitly, especially for VS 18 builds:
+
+   ```powershell
+   python Build\setup_glass.py --buildOutput BuildOutput\Debug18.0\raw\binaries
+   ```
+
+3. If setup needs internal drop access, provide an auth token environment variable or allow the interactive credential flow:
+
+   ```powershell
+   python Build\setup_glass.py --authTokenVariable SYSTEM_ACCESSTOKEN --buildOutput <path-to-raw-binaries>
+   ```
+
+4. List discovered tests after setup:
+
+   ```powershell
+   python Build\setup_glass.py --verifyListing
+   ```
+
+5. Run all tests or a single test:
+
+   ```powershell
+   python Build\run_glass.py --buildOutput BuildOutput\Debug18.0\raw\binaries
+   python Build\run_glass.py --buildOutput BuildOutput\Debug18.0\raw\binaries Repr_Bytes-311-64
+   ```
+
+## CI Failure Workflow
+
+1. Start with the PR log and `TestResults/PythonTests.trx`.
+2. Classify the failure:
+   - Setup/drop/auth failure before `vstest.console.exe` starts.
+   - Discovery/adapter failure after `vstest.console.exe` starts but before individual tests run.
+   - `glass2.exe` or `TestScript.xml` failure inside a specific test case.
+3. Check [Build/templates/run_tests.yml](../../../Build/templates/run_tests.yml) to see whether `GlassTests` came from cache. Cache hits skip `setup_glass.py`, but `run_glass.py` still calls `copy_ptvs_output()`.
+4. For assembly binding errors, inspect every `Newtonsoft.Json.dll` under `GlassTests` and compare assembly versions. `Glass.TestAdapter.dll` expects `Newtonsoft.Json, Version=13.0.0.0`; NuGet/vstest VSIX extraction can place older 9.x or 10.x copies in the runner tree. The compatible copy usually comes from `GlassTests\Glass\Newtonsoft.Json.dll`.
+5. Do not assume a PTVS NuGet restore or package update will fix Glass runner dependency conflicts. The failing assembly may come from downloaded Glass/NuGet/vstest VSIX payloads, not from `packages/`.
+
+## Debugging TestScript Failures
+
+1. Reproduce one test at a time with `python Build\run_glass.py --buildOutput <path> <test-name>`.
+2. Inspect the failing test's `TestScript.xml` and source files under `Python/Tests/GlassTests/PythonTests/`.
+3. Compare the error log against expected events, source file names, line numbers, breakpoints, and function names in the script.
+4. Look for generated logs, dumps, and copied debuggee files under the runtime `GlassTests\PythonTests\...\obj\<configuration>\` and `bin\<configuration>\` paths.
+5. To debug Glass itself, set `GLASS_DEBUG=1`, rerun one test, attach Visual Studio to `glass2.exe`, and check assertions or event handling.
+6. To debug with the real product, follow [Python/Tests/GlassTests/readme.txt](../../../Python/Tests/GlassTests/readme.txt): run PTVS under the debugger, open the generated test folder, mirror the `TestScript.xml` breakpoints, and use `launch.vs.json` with the intended interpreter.
+
+## Common Pitfalls
+
+- Full setup is Microsoft-internal because `drop.exe` downloads from internal DevDiv artifact drops.
+- `run_glass.py` without `--buildOutput` historically probes 17.0 build output paths; pass `--buildOutput` for local VS 18 builds.
+- `EnvironmentDiscover.exe not found` usually means the build output path is wrong or stale.
+- `PythonConcord.GlassTestRoot` or `PythonEngine.regdef` missing means the runtime test copy is incomplete or setup did not run successfully.
+- Cache hits can preserve stale `GlassTests` contents. Fixes that must run before test execution should be in the `run_glass.py` path, usually via `copy_ptvs_output()`.
+- Runtime files under `GlassTests/` are generated and cacheable; source test changes belong under `Python/Tests/GlassTests/`.

.github/instructions/chat-customizations.instructions.md

@@ -0,0 +1,11 @@
+---
+description: "Use when creating or updating PTVS chat customization files, including SKILL.md files, .claude/skills, .github/skills, prompts, instructions, and custom agents."
+applyTo: [".claude/skills/**/SKILL.md", ".github/skills/**/SKILL.md", ".agents/skills/**/SKILL.md"]
+---
+# PTVS Chat Customization Guidelines
+
+- Put project skills under `.claude/skills/<skill-name>/SKILL.md` unless the user explicitly asks for another host location.
+- Do not leave duplicate skill copies under `.github/skills` or `.agents/skills` after moving a skill to `.claude/skills`.
+- Keep chat customization changes scoped to customization files; do not modify product, build, test, or package files while handling a customization-only request.
+- Link to existing repo documentation instead of copying it into customization files.
+- After creating or moving a skill, validate that the folder name matches the `name` frontmatter and that relative links still resolve from the new location.

package.json

@@ -2,6 +2,6 @@
     "name":  "ptvs",
     "private":  true,
     "devDependencies":  {
-                            "@pylance/pylance":  "2026.1.1"
+                            "@pylance/pylance":  "2026.2.1"
                         }
 }