Inline BootstrapCommand::force_coloring_in_ci into its only call site

This logic is cargo-specific anyway, so there is no need for it to be a
generally-available helper method.

Author: Zalathar

src/bootstrap/src/core/builder/cargo.rs

@@ -2,6 +2,8 @@ use std::env;
 use std::ffi::{OsStr, OsString};
 use std::path::{Path, PathBuf};
 
+use build_helper::ci::CiEnv;
+
 use super::{Builder, Kind};
 use crate::core::build_steps::test;
 use crate::core::build_steps::tool::SourceType;
@@ -1334,7 +1336,13 @@ impl Builder<'_> {
         // Try to use a sysroot-relative bindir, in case it was configured absolutely.
         cargo.env("RUSTC_INSTALL_BINDIR", self.config.bindir_relative());
 
-        cargo.force_coloring_in_ci();
+        if CiEnv::is_ci() {
+            // Tell cargo to use colored output for nicer logs in CI, even
+            // though CI isn't printing to a terminal.
+            // Also set an explicit `TERM=xterm` so that cargo doesn't warn
+            // about TERM not being set.
+            cargo.env("TERM", "xterm").args(["--color=always"]);
+        };
 
         // When we build Rust dylibs they're all intended for intermediate
         // usage, so make sure we pass the -Cprefer-dynamic flag instead of

src/bootstrap/src/utils/exec.rs

@@ -21,7 +21,6 @@ use std::process::{
 use std::sync::{Arc, Mutex};
 use std::time::{Duration, Instant};
 
-use build_helper::ci::CiEnv;
 use build_helper::drop_bomb::DropBomb;
 use build_helper::exit;
 
@@ -390,18 +389,6 @@ impl<'a> BootstrapCommand {
         self.drop_bomb.get_created_location()
     }
 
-    /// If in a CI environment, forces the command to run with colors.
-    pub fn force_coloring_in_ci(&mut self) {
-        if CiEnv::is_ci() {
-            // Due to use of stamp/docker, the output stream of bootstrap is not
-            // a TTY in CI, so coloring is by-default turned off.
-            // The explicit `TERM=xterm` environment is needed for
-            // `--color always` to actually work. This env var was lost when
-            // compiling through the Makefile. Very strange.
-            self.env("TERM", "xterm").args(["--color", "always"]);
-        }
-    }
-
     pub fn fingerprint(&self) -> CommandFingerprint {
         let command = &self.command;
         CommandFingerprint {