From 35d6bd761b3a41bd7dca8a37824fc06e8a2022cb Mon Sep 17 00:00:00 2001
From: konsti <konstin@mailbox.org>
Date: Mon, 30 Oct 2023 20:10:01 +0100
Subject: [PATCH] Fallback to copy if hardlinking failed (#237)

---
 crates/install-wheel-rs/src/linker.rs    | 12 +++++++++++-
 crates/puffin-installer/src/installer.rs |  7 +++++--
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/crates/install-wheel-rs/src/linker.rs b/crates/install-wheel-rs/src/linker.rs
index 6856d8776..e702d98b5 100644
--- a/crates/install-wheel-rs/src/linker.rs
+++ b/crates/install-wheel-rs/src/linker.rs
@@ -361,6 +361,9 @@ fn hardlink_wheel_files(
 ) -> Result<usize, Error> {
     let mut count = 0usize;
 
+    // Avoid causing the same error for every file
+    let mut use_copy_fallback = false;
+
     // Walk over the directory.
     for entry in walkdir::WalkDir::new(&wheel) {
         let entry = entry?;
@@ -375,8 +378,15 @@ fn hardlink_wheel_files(
         // Hardlink the file, unless it's the `RECORD` file, which we modify during installation.
         if entry.path().ends_with("RECORD") {
             fs::copy(entry.path(), &out_path)?;
+        } else if use_copy_fallback {
+            fs::copy(entry.path(), &out_path)?;
         } else {
-            fs::hard_link(entry.path(), &out_path)?;
+            let hard_link_result = fs::hard_link(entry.path(), &out_path);
+            // Once https://github.com/rust-lang/rust/issues/86442 is stable, use that
+            if hard_link_result.is_err() {
+                fs::copy(entry.path(), &out_path)?;
+                use_copy_fallback = true;
+            }
         }
 
         count += 1;
diff --git a/crates/puffin-installer/src/installer.rs b/crates/puffin-installer/src/installer.rs
index f8d7df607..b81b3fd43 100644
--- a/crates/puffin-installer/src/installer.rs
+++ b/crates/puffin-installer/src/installer.rs
@@ -1,4 +1,4 @@
-use anyhow::{Error, Result};
+use anyhow::{Context, Error, Result};
 use rayon::iter::{IntoParallelRefIterator, ParallelIterator};
 
 use pep440_rs::Version;
@@ -47,7 +47,10 @@ impl<'a> Installer<'a> {
                     self.venv.interpreter_info().simple_version(),
                 );
 
-                install_wheel_rs::linker::install_wheel(&location, wheel.path(), self.link_mode)?;
+                install_wheel_rs::linker::install_wheel(&location, wheel.path(), self.link_mode)
+                    .with_context(|| {
+                        format!("Failed to install {} {}", wheel.name(), wheel.version())
+                    })?;
 
                 if let Some(reporter) = self.reporter.as_ref() {
                     reporter.on_install_progress(wheel.name(), wheel.version());