From 44f4dcc6f7dd3c68f7cb593b46ae73d1b442d8ad Mon Sep 17 00:00:00 2001
From: Joshua Barretto <joshua.s.barretto@gmail.com>
Date: Wed, 18 Jan 2023 22:01:00 +0000
Subject: [PATCH 1/2] Added canary asset

---
 .gitattributes              |  1 +
 assets/common/canary.canary |  3 +++
 common/assets/src/fs.rs     | 14 +++++++++++++-
 common/assets/src/lib.rs    |  6 ++++++
 4 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 assets/common/canary.canary

diff --git a/.gitattributes b/.gitattributes
index 6aefa43907..9a6ab1cf2f 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -9,6 +9,7 @@
 *.tar filter=lfs diff=lfs merge=lfs -text
 *.obj filter=lfs diff=lfs merge=lfs -text
 *.blend filter=lfs diff=lfs merge=lfs -text
+*.canary filter=lfs diff=lfs merge=lfs -text
 assets/world/map/*.bin filter=lfs diff=lfs merge=lfs -text
 
 *.ron gitlab-language=rust
diff --git a/assets/common/canary.canary b/assets/common/canary.canary
new file mode 100644
index 0000000000..2db11972f0
--- /dev/null
+++ b/assets/common/canary.canary
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:97113cf6c0e999a0eece8c1d10847306bba1cbfbb8618aa92d4fd3f9b5b2813d
+size 480
diff --git a/common/assets/src/fs.rs b/common/assets/src/fs.rs
index 7a3662d76f..b5cef02cbd 100644
--- a/common/assets/src/fs.rs
+++ b/common/assets/src/fs.rs
@@ -1,4 +1,4 @@
-use std::{borrow::Cow, io};
+use std::{borrow::Cow, fs, io};
 
 use assets_manager::{
     hot_reloading::{DynUpdateSender, EventSender, FsWatcherBuilder},
@@ -23,6 +23,18 @@ impl FileSystem {
                 .ok()
         });
 
+        let canary = fs::read_to_string(super::ASSETS_PATH.join("common").join("canary.canary"))
+            .map_err(|e| {
+                io::Error::new(
+                    io::ErrorKind::Other,
+                    format!("failed to load canary asset: {}", e),
+                )
+            })?;
+
+        if !canary.starts_with("VELOREN_CANARY_MAGIC") {
+            panic!("Canary asset `canary.canary` was present but did not contain the expected data. This *heavily* implies that you've not correctly set up Git LFS (Large File Storage). Visit `https://book.veloren.net/contributors/development-tools.html#git-lfs` for more information about setting up Git LFS.");
+        }
+
         Ok(Self {
             default,
             override_dir,
diff --git a/common/assets/src/lib.rs b/common/assets/src/lib.rs
index e25fa101da..ee86ec8c2b 100644
--- a/common/assets/src/lib.rs
+++ b/common/assets/src/lib.rs
@@ -305,6 +305,12 @@ mod tests {
     use std::{ffi::OsStr, fs::File};
     use walkdir::WalkDir;
 
+    #[test]
+    fn load_canary() {
+        // Loading the asset cache will automatically cause the canary to load
+        let _ = *super::ASSETS;
+    }
+
     /// Fail unless all `.ron` asset files successfully parse to `ron::Value`.
     #[test]
     fn parse_all_ron_files_to_value() {

From 63d0c937f05361b81d3b6d5934c1f50eedf86bbe Mon Sep 17 00:00:00 2001
From: Joshua Barretto <joshua.s.barretto@gmail.com>
Date: Wed, 18 Jan 2023 22:31:33 +0000
Subject: [PATCH 2/2] Removed existing LFS check

---
 common/build.rs | 40 +---------------------------------------
 flake.nix       |  3 ---
 2 files changed, 1 insertion(+), 42 deletions(-)

diff --git a/common/build.rs b/common/build.rs
index 71e4750974..1916c4b808 100644
--- a/common/build.rs
+++ b/common/build.rs
@@ -1,10 +1,4 @@
-use std::{
-    env,
-    fs::File,
-    io::{Read, Write},
-    path::{Path, PathBuf},
-    process::Command,
-};
+use std::{env, fs::File, io::Write, path::Path, process::Command};
 
 fn main() {
     // If these env variables exist then we are building on nix, use them as hash
@@ -52,38 +46,6 @@ fn main() {
             Err(e) => panic!("failed to retrieve current git commit hash: {}", e),
         }
     }
-
-    // Check if git-lfs is working
-    if env::var("DISABLE_GIT_LFS_CHECK").is_err() && cfg!(not(feature = "no-assets")) {
-        let asset_path: PathBuf = ["..", "assets", "voxygen", "background", "bg_main.jpg"]
-            .iter()
-            .collect();
-        let asset_file = match File::open(&asset_path) {
-            Ok(file) => file,
-            Err(e) => panic!(
-                "failed to open asset file {}: {}",
-                asset_path.to_str().unwrap(),
-                e
-            ),
-        };
-        const LFS_MARKER: &[u8] = b"version https://git-lfs.github.com/spec/";
-        let mut buffer = Vec::new();
-        let bytes_read = asset_file
-            .take(LFS_MARKER.len() as u64)
-            .read_to_end(&mut buffer)
-            .expect("failed to read asset file");
-
-        if bytes_read == LFS_MARKER.len() && buffer == LFS_MARKER {
-            panic!(
-                "\n\nGit Large File Storage (git-lfs) has not been set up correctly.\n\
-                 Most common reasons:\n\
-                 \t- git-lfs was not installed before cloning this repository\n\
-                 \t- this repository was not cloned from the primary gitlab mirror.\n\
-                 \t  The github mirror does not support lfs.\n\
-                 See the book at https://book.veloren.net/ for details.\n\n"
-            );
-        }
-    }
 }
 
 fn create_hash_file(hash: &str) {
diff --git a/flake.nix b/flake.nix
index 691249a142..9a69eac388 100644
--- a/flake.nix
+++ b/flake.nix
@@ -86,9 +86,6 @@
       pkgConfig = common: let
         inherit (common) pkgs;
         veloren-common-ov = {
-          # Disable `git-lfs` check here since we check it ourselves
-          # We have to include the command output here, otherwise Nix won't run it
-          DISABLE_GIT_LFS_CHECK = true;
           # We don't add in any information here because otherwise anything
           # that depends on common will be recompiled. We will set these in
           # our wrapper instead.