Remove host and target configuration from config.txt

They can still be set using HOST_TRIPLE and TARGET_TRIPLE.

Author: bjorn3

build_system/main.rs

@@ -156,10 +156,8 @@ fn main() {
         let cargo = rustc_info::get_cargo_path();
         let rustc = rustc_info::get_rustc_path();
         let rustdoc = rustc_info::get_rustdoc_path();
-        let triple = std::env::var("HOST_TRIPLE")
-            .ok()
-            .or_else(|| config::get_value("host"))
-            .unwrap_or_else(|| rustc_info::get_host_triple(&rustc));
+        let triple =
+            std::env::var("HOST_TRIPLE").unwrap_or_else(|_| rustc_info::get_host_triple(&rustc));
         Compiler {
             cargo,
             rustc,
@@ -170,10 +168,8 @@ fn main() {
             runner: vec![],
         }
     };
-    let target_triple = std::env::var("TARGET_TRIPLE")
-        .ok()
-        .or_else(|| config::get_value("target"))
-        .unwrap_or_else(|| bootstrap_host_compiler.triple.clone());
+    let target_triple =
+        std::env::var("TARGET_TRIPLE").unwrap_or_else(|_| bootstrap_host_compiler.triple.clone());
 
     let dirs = path::Dirs {
         source_dir: current_dir.clone(),

config.txt

@@ -1,20 +1,10 @@
 # This file allows configuring the build system.
 
-# Which triple to produce a compiler toolchain for.
-#
-# Defaults to the default triple of rustc on the host system.
-#host = x86_64-unknown-linux-gnu
-
-# Which triple to build libraries (core/alloc/std/test/proc_macro) for.
-#
-# Defaults to `host`.
-#target = x86_64-unknown-linux-gnu
-
 # Disables cleaning of the sysroot dir. This will cause old compiled artifacts to be re-used when
 # the sysroot source hasn't changed. This is useful when the codegen backend hasn't been modified.
 # This option can be changed while the build system is already running for as long as sysroot
 # building hasn't started yet.
-#keep_sysroot
+keep_sysroot
 
 
 # Testsuite