Move force_coloring_in_ci from builder_helper to bootstrap

It was only used in bootstrap. This move allows us to modify the function to work with `BootstrapCommand`, rather than `Command`.

src/bootstrap/src/core/build_steps/test.rs

@@ -25,7 +25,7 @@ use crate::core::builder::{Builder, Compiler, Kind, RunConfig, ShouldRun, Step};
 use crate::core::config::flags::get_completion;
 use crate::core::config::flags::Subcommand;
 use crate::core::config::TargetSelection;
-use crate::utils::exec::{command, BootstrapCommand};
+use crate::utils::exec::{command, force_coloring_in_ci, BootstrapCommand};
 use crate::utils::helpers::{
     self, add_link_lib_path, add_rustdoc_cargo_linker_args, dylib_path, dylib_path_var,
     linker_args, linker_flags, t, target_supports_cranelift_backend, up_to_date, LldThreads,
@@ -2096,8 +2096,7 @@ NOTE: if you're sure you want to do this, please open an issue as to why. In the
         cmd.arg("--git-repository").arg(git_config.git_repository);
         cmd.arg("--nightly-branch").arg(git_config.nightly_branch);
 
-        // FIXME: Move CiEnv back to bootstrap, it is only used here anyway
-        builder.ci_env.force_coloring_in_ci(cmd.as_command_mut());
+        force_coloring_in_ci(builder.ci_env, &mut cmd);
 
         #[cfg(feature = "build-metrics")]
         builder.metrics.begin_test_suite(

src/bootstrap/src/core/builder.rs

@@ -24,7 +24,7 @@ use crate::utils::helpers::{check_cfg_arg, libdir, linker_flags, t, LldThreads};
 use crate::EXTRA_CHECK_CFGS;
 use crate::{Build, CLang, Crate, DocTests, GitRepo, Mode};
 
-use crate::utils::exec::{command, BootstrapCommand};
+use crate::utils::exec::{command, force_coloring_in_ci, BootstrapCommand};
 pub use crate::Compiler;
 
 use clap::ValueEnum;
@@ -2105,7 +2105,7 @@ impl<'a> Builder<'a> {
         // Try to use a sysroot-relative bindir, in case it was configured absolutely.
         cargo.env("RUSTC_INSTALL_BINDIR", self.config.bindir_relative());
 
-        self.ci_env.force_coloring_in_ci(cargo.as_command_mut());
+        force_coloring_in_ci(self.ci_env, &mut cargo);
 
         // 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

@@ -1,4 +1,5 @@
 use crate::Build;
+use build_helper::ci::CiEnv;
 use build_helper::drop_bomb::DropBomb;
 use std::ffi::OsStr;
 use std::fmt::{Debug, Formatter};
@@ -286,3 +287,15 @@ impl From<Output> for CommandOutput {
         }
     }
 }
+
+/// If in a CI environment, forces the command to run with colors.
+pub fn force_coloring_in_ci(ci_env: CiEnv, cmd: &mut BootstrapCommand) {
+    if ci_env != CiEnv::None {
+        // 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.
+        cmd.env("TERM", "xterm").args(["--color", "always"]);
+    }
+}

src/tools/build_helper/src/ci.rs

@@ -1,5 +1,3 @@
-use std::process::Command;
-
 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
 pub enum CiEnv {
     /// Not a CI environment.
@@ -21,18 +19,6 @@ impl CiEnv {
     pub fn is_ci() -> bool {
         Self::current() != CiEnv::None
     }
-
-    /// If in a CI environment, forces the command to run with colors.
-    pub fn force_coloring_in_ci(self, cmd: &mut Command) {
-        if self != CiEnv::None {
-            // 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.
-            cmd.env("TERM", "xterm").args(&["--color", "always"]);
-        }
-    }
 }
 
 pub mod gha {