feat: friendlier trouble shooting guide

Author: matklad

docs/user/manual.adoc

@@ -139,14 +139,38 @@ $ cargo xtask install --server
 
 ==== Troubleshooting
 
-Here are some useful self-diagnostic commands:
-
-* **Rust Analyzer: Show RA Version** shows the version of `rust-analyzer` binary.
-* **Rust Analyzer: Status** prints some statistics about the server, and dependency information for the current file.
-* To enable server-side logging, run with `env RA_LOG=info` and see `Output > Rust Analyzer Language Server` in VS Code's panel.
-* To log project loading (sysroot & `cargo metadata`), set `RA_LOG=project_model=debug`.
-* To log all LSP requests, add `"rust-analyzer.trace.server": "verbose"` to the settings and look for `Rust Analyzer Language Server Trace` in the panel.
-* To enable client-side logging, add `"rust-analyzer.trace.extension": true` to the settings and open `Output > Rust Analyzer Client` in the panel.
+Start with looking at the rust-analyzer version.
+Try **Rust Analyzer: Show RA Version** and `rust-analyzer --version` in the command line.
+If the date is more than a week ago, it's better to update rust-analyzer version.
+
+The next thing to check would be panic messages in rust-analyzer's log.
+Log messages are printed to stderr, in VS Code you can see then in the `Output > Rust Analyzer Language Server` tab of the panel.
+To see more logs, set `RA_LOG=info` environmental variable.
+
+To fully capture LSP messages between the editor and the server, set `"rust-analyzer.trace.server": "verbose"` config and check
+`Output > Rust Analyzer Language Server Trace`.
+
+The root cause for many "`nothing works`" problems is that rust-analyzer fails to understand the project structure.
+To debug that, first note the `rust-analyzer` section in the status bar.
+If it has an error icon and red, that's the problem (hover will have somewhat helpful error message).
+**Rust Analyzer: Status** prints dependency information for the current file.
+Finally, `RA_LOG=project_model=debug` enables verbose logs during project loading.
+
+If rust-analyzer outright crashes, try running `rust-analyzer analysis-stats /path/to/project/directory/` on the command line.
+This command type checks the whole project in batch mode bypassing LSP machinery.
+
+When filing issues, it is useful (but not necessary) to try to minimize examples.
+An ideal bug reproduction looks like this:
+
+```bash
+$ git clone https://github.com/username/repo.git && cd repo && git switch --detach commit-hash
+$ rust-analyzer --version
+rust-analyzer dd12184e4 2021-05-08 dev
+$ rust-analyzer analysis-stats .
+💀 💀 💀
+```
+
+It is especially useful when the `repo` doesn't use external crates or the standard library.
 
 === rust-analyzer Language Server Binary