Open with (detached) custom viewers and raise error on failure (#4430)

crates/typst-cli/src/args.rs

@@ -100,9 +100,11 @@ pub struct CompileCommand {
     #[arg(long = "format", short = 'f')]
     pub format: Option<OutputFormat>,
 
-    /// Opens the output file using the default viewer after compilation.
-    /// Ignored if output is stdout
-    #[arg(long = "open")]
+    /// Opens the output file with the default viewer or a specific program after
+    /// compilation
+    ///
+    /// Ignored if output is stdout.
+    #[arg(long = "open", value_name = "VIEWER")]
     pub open: Option<Option<String>>,
 
     /// The PPI (pixels per inch) to use for PNG export

crates/typst-cli/src/compile.rs

@@ -472,14 +472,30 @@ fn write_make_deps(world: &mut SystemWorld, command: &CompileCommand) -> StrResu
 /// Opens the given file using:
 /// - The default file viewer if `open` is `None`.
 /// - The given viewer provided by `open` if it is `Some`.
+///
+/// If the file could not be opened, an error is returned.
 fn open_file(open: Option<&str>, path: &Path) -> StrResult<()> {
+    // Some resource openers require the path to be canonicalized.
+    let path = path
+        .canonicalize()
+        .map_err(|err| eco_format!("failed to canonicalize path ({err})"))?;
     if let Some(app) = open {
-        open::with_in_background(path, app);
+        open::with_detached(&path, app)
+            .map_err(|err| eco_format!("failed to open file with {} ({})", app, err))
     } else {
-        open::that_in_background(path);
+        open::that_detached(&path).map_err(|err| {
+            let openers = open::commands(path)
+                .iter()
+                .map(|command| command.get_program().to_string_lossy())
+                .collect::<Vec<_>>()
+                .join(", ");
+            eco_format!(
+                "failed to open file with any of these resource openers: {} ({})",
+                openers,
+                err,
+            )
+        })
     }
-
-    Ok(())
 }
 
 /// Adds useful hints when the main source file couldn't be read