Auto merge of #127152 - ChrisDenton:rename, r=<try>

Bootstrap: Try renaming the file if removing fails

Second attempt at working around #127126

If we can't remove the file, then try renaming it. This will leave the destination path free to use.

try-job: x86_64-msvc-ext

src/bootstrap/src/lib.rs

@@ -26,6 +26,7 @@ use std::path::{Path, PathBuf};
 use std::process::{Command, Stdio};
 use std::str;
 use std::sync::OnceLock;
+use std::time::SystemTime;
 
 use build_helper::ci::{gha, CiEnv};
 use build_helper::exit;
@@ -1676,7 +1677,14 @@ impl Build {
         if src == dst {
             return;
         }
-        let _ = fs::remove_file(dst);
+        if fs::remove_file(dst).is_err() {
+            // workaround for https://github.com/rust-lang/rust/issues/127126
+            // if removing the file fails, attempt to rename it instead.
+            let now = SystemTime::now()
+                .duration_since(SystemTime::UNIX_EPOCH)
+                .expect("couldn't get system time");
+            let _ = fs::rename(dst, format!("{}-{}", dst.display(), now.as_nanos()));
+        }
         let metadata = t!(src.symlink_metadata(), format!("src = {}", src.display()));
         let mut src = src.to_path_buf();
         if metadata.file_type().is_symlink() {