feat(config): Allow overriding unicode detection

src/cargo/core/shell.rs

@@ -251,6 +251,19 @@ impl Shell {
         Ok(())
     }
 
+    pub fn set_unicode(&mut self, yes: bool) -> CargoResult<()> {
+        if let ShellOut::Stream {
+            ref mut stdout_unicode,
+            ref mut stderr_unicode,
+            ..
+        } = self.output
+        {
+            *stdout_unicode = yes;
+            *stderr_unicode = yes;
+        }
+        Ok(())
+    }
+
     pub fn set_hyperlinks(&mut self, yes: bool) -> CargoResult<()> {
         if let ShellOut::Stream {
             ref mut hyperlinks, ..

src/cargo/util/context/mod.rs

@@ -1049,6 +1049,9 @@ impl GlobalContext {
         if let Some(hyperlinks) = term.hyperlinks {
             self.shell().set_hyperlinks(hyperlinks)?;
         }
+        if let Some(unicode) = term.unicode {
+            self.shell().set_unicode(unicode)?;
+        }
 
         self.progress_config = term.progress.unwrap_or_default();
 
@@ -2646,6 +2649,7 @@ pub struct TermConfig {
     pub quiet: Option<bool>,
     pub color: Option<String>,
     pub hyperlinks: Option<bool>,
+    pub unicode: Option<bool>,
     #[serde(default)]
     #[serde(deserialize_with = "progress_or_string")]
     pub progress: Option<ProgressConfig>,

src/doc/src/reference/config.md

@@ -182,6 +182,7 @@ quiet = false          # whether cargo output is quiet
 verbose = false        # whether cargo provides verbose output
 color = 'auto'         # whether cargo colorizes output
 hyperlinks = true      # whether cargo inserts links into output
+unicode = true         # whether cargo can render output using non-ASCII unicode characters
 progress.when = 'auto' # whether cargo shows progress bar
 progress.width = 80    # width of progress bar
 ```
@@ -1298,6 +1299,13 @@ Can be overridden with the `--color` command-line option.
 
 Controls whether or not hyperlinks are used in the terminal.
 
+#### `term.unicode`
+* Type: bool
+* Default: auto-detect
+* Environment: `CARGO_TERM_UNICODE`
+
+Control whether output can be rendered using non-ASCII unicode characters.
+
 #### `term.progress.when`
 * Type: string
 * Default: "auto"