From f4d85d1e3a56e932b8b548635f6fbde2eccd8cba Mon Sep 17 00:00:00 2001
From: Akash Satheesan <akash@coder.com>
Date: Wed, 14 Apr 2021 16:22:54 +0530
Subject: [PATCH] fix(update-vscode): add check/docs for git-subtree

---
 ci/dev/update-vscode.sh | 14 +++++++++++++-
 docs/CONTRIBUTING.md    |  3 +++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/ci/dev/update-vscode.sh b/ci/dev/update-vscode.sh
index 65daedcc3a0e..1b60d57c2df5 100755
--- a/ci/dev/update-vscode.sh
+++ b/ci/dev/update-vscode.sh
@@ -56,8 +56,20 @@ main() {
     echo "jq could not be found."
     echo "We use this when looking up the exact version to update to in the package.json in VS Code."
     echo -e "See docs here: https://stedolan.github.io/jq/download/"
-    exit
+    exit 1
+  fi
+
+  # Note: `git subtree` returns 129 when installed, and prints help;
+  # but when uninstalled, returns 1.
+  set +e
+  git subtree &>/dev/null
+  if [ $? -ne 129 ]; then
+    echo "git-subtree could not be found."
+    echo "We use this to fetch and update the lib/vscode subtree."
+    echo -e "Please install git subtree."
+    exit 1
   fi
+  set -e
 
   # Grab the exact version from package.json
   VSCODE_EXACT_VERSION=$(curl -s "https://raw.githubusercontent.com/microsoft/vscode/release/$VSCODE_VERSION_TO_UPDATE/package.json" | jq -r ".version")
diff --git a/docs/CONTRIBUTING.md b/docs/CONTRIBUTING.md
index 15c997fd64b5..d909521694fd 100644
--- a/docs/CONTRIBUTING.md
+++ b/docs/CONTRIBUTING.md
@@ -59,6 +59,9 @@ To develop inside an isolated Docker container:
 
 ### Updating VS Code
 
+Updating VS Code requires `git subtree`. On some rpm-based Linux distros, `git subtree` is not included by default, and needs to be installed separately.
+To install, run `dnf install git-subtree` or `yum install git-subtree` as necessary.
+
 To update VS Code, follow these steps:
 
 1. Run `yarn update:vscode`.