Fix a TOCTOU occurence

Author: bjorn3

build_system/prepare.rs

@@ -6,14 +6,14 @@ use std::process::{Command, Stdio};
 use super::build_sysroot::{BUILD_SYSROOT, ORIG_BUILD_SYSROOT, SYSROOT_RUSTC_VERSION, SYSROOT_SRC};
 use super::path::{Dirs, RelPath};
 use super::rustc_info::{get_default_sysroot, get_rustc_version};
-use super::utils::{copy_dir_recursively, git_command, retry_spawn_and_wait, spawn_and_wait};
+use super::utils::{
+    copy_dir_recursively, git_command, remove_file_if_exists, retry_spawn_and_wait, spawn_and_wait,
+};
 
 pub(crate) fn prepare(dirs: &Dirs, vendor: bool) {
     RelPath::DOWNLOAD.ensure_fresh(dirs);
 
-    if Path::new(".cargo/config.toml").exists() {
-        std::fs::remove_file(".cargo/config.toml").unwrap();
-    }
+    remove_file_if_exists(Path::new(".cargo/config.toml"));
 
     let mut cargo_workspaces = vec![super::build_backend::CG_CLIF.manifest_path(dirs)];
 

build_system/utils.rs

@@ -237,6 +237,14 @@ pub(crate) fn spawn_and_wait_with_input(mut cmd: Command, input: String) -> Stri
     String::from_utf8(output.stdout).unwrap()
 }
 
+pub(crate) fn remove_file_if_exists(path: &Path) {
+    match fs::remove_file(&path) {
+        Ok(()) => {}
+        Err(err) if err.kind() == io::ErrorKind::NotFound => {}
+        Err(err) => panic!("Failed to remove {path}: {err}", path = path.display()),
+    }
+}
+
 pub(crate) fn remove_dir_if_exists(path: &Path) {
     match fs::remove_dir_all(&path) {
         Ok(()) => {}