Cleanup usage of unwrap() in re_dev_tools (rerun-io#6337)

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### What

Part of rerun-io#6330
Removes or explicitly allows unwrap() where it makes sense.

### Checklist
* [x] I have read and agree to [Contributor
Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)
* [x] I've included a screenshot or gif (if applicable)
* [x] I have tested the web demo (if applicable):
* Using examples from latest `main` build:
[rerun.io/viewer](https://rerun.io/viewer/pr/6337?manifest_url=https://app.rerun.io/version/main/examples_manifest.json)
* Using full set of examples from `nightly` build:
[rerun.io/viewer](https://rerun.io/viewer/pr/6337?manifest_url=https://app.rerun.io/version/nightly/examples_manifest.json)
* [x] The PR title and labels are set such as to maximize their
usefulness for the next release's CHANGELOG
* [x] If applicable, add a new check to the [release
checklist](https://github.com/rerun-io/rerun/blob/main/tests/python/release_checklist)!

- [PR Build Summary](https://build.rerun.io/pr/6337)
- [Recent benchmark results](https://build.rerun.io/graphs/crates.html)
- [Wasm size tracking](https://build.rerun.io/graphs/sizes.html)

To run all checks from `main`, comment on the PR with `@rerun-bot
full-check`.

---------

Co-authored-by: Andreas Reich <[email protected]>
Co-authored-by: Andreas Reich <[email protected]>

crates/re_dev_tools/src/build_examples/example.rs

@@ -379,10 +379,9 @@ impl Frontmatter {
 
         let frontmatter: Frontmatter =
             toml::from_str(content[start..end].trim()).map_err(|err| {
-                anyhow::anyhow!(
-                    "Failed to parse TOML metadata of {:?}: {err}",
-                    path.parent().unwrap().file_name().unwrap()
-                )
+                #[allow(clippy::unwrap_used)]
+                let p = path.parent().unwrap().file_name().unwrap();
+                anyhow::anyhow!("Failed to parse TOML metadata of {p:?}: {err}")
             })?;
 
         Ok(Some((

crates/re_dev_tools/src/build_examples/snippets.rs

@@ -79,6 +79,7 @@ fn collect_snippets_recursively(
 ) -> anyhow::Result<Vec<Snippet>> {
     let mut snippets = vec![];
 
+    #[allow(clippy::unwrap_used)] // we just use unwrap for string <-> path conversion here
     for snippet in dir.read_dir()? {
         let snippet = snippet?;
         let meta = snippet.metadata()?;

crates/re_dev_tools/src/build_search_index/ingest.rs

@@ -1,3 +1,5 @@
+#![allow(clippy::unwrap_used)] // build tool, so okay here
+
 /// Docs read from `/docs`
 mod docs;
 

crates/re_dev_tools/src/build_search_index/ingest/cpp.rs

@@ -1,3 +1,5 @@
+#![allow(clippy::unwrap_used)] // build tool, so okay here
+
 use super::Context;
 use super::DocumentData;
 use super::DocumentKind;

crates/re_dev_tools/src/build_search_index/ingest/docs.rs

@@ -1,3 +1,5 @@
+#![allow(clippy::unwrap_used)] // build tool, so okay here
+
 use super::{Context, DocumentData, DocumentKind};
 use crate::build_search_index::util::ProgressBarExt as _;
 use std::path::Path;

crates/re_dev_tools/src/build_search_index/ingest/rust.rs

@@ -1,3 +1,5 @@
+#![allow(clippy::unwrap_used)] // build tool, so okay here
+
 use super::{Context, DocumentData, DocumentKind};
 use crate::build_search_index::util::ProgressBarExt as _;
 use anyhow::Context as _;

crates/re_dev_tools/src/build_search_index/meili.rs

@@ -194,7 +194,9 @@ impl Task {
             TaskStatus::Succeeded => Ok(ControlFlow::Break(())),
 
             TaskStatus::Failed => {
-                anyhow::bail!("task failed: {}", self.error.as_ref().unwrap().message)
+                #[allow(clippy::unwrap_used)]
+                let msg = self.error.as_ref().unwrap().message.as_str();
+                anyhow::bail!("task failed: {}", msg)
             }
             TaskStatus::Canceled => anyhow::bail!("task was canceled"),
         }

crates/re_dev_tools/src/build_search_index/repl.rs

@@ -49,8 +49,8 @@ impl Repl {
 
         let mut lines = stdin().lines();
         loop {
-            stdout().write_all(b"\n> ").unwrap();
-            stdout().flush().unwrap();
+            stdout().write_all(b"\n> ")?;
+            stdout().flush()?;
 
             match lines.next().transpose()? {
                 Some(line) => match self.handle_line(&client, &line)? {

crates/re_dev_tools/src/main.rs

@@ -1,10 +1,6 @@
 //! Crate that combines several development utilities.
 //!
 //! To get an overview over all tools run `pixi run dev-tools --help`.
-
-// TODO(#3408): remove unwrap()
-#![allow(clippy::unwrap_used)]
-
 use argh::FromArgs;
 
 mod build_examples;