From 9f92ec2651e4c2310051fa3ab847dd9bbf72b0f4 Mon Sep 17 00:00:00 2001
From: Dmitry Mostovenko <trueberserker@gmail.com>
Date: Thu, 23 Apr 2020 22:53:31 +0300
Subject: [PATCH] Add error message about missing unzip utility (#55315)

---
 bin/internal/update_dart_sdk.sh | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/bin/internal/update_dart_sdk.sh b/bin/internal/update_dart_sdk.sh
index cdbdac2fef..f45b15b9af 100755
--- a/bin/internal/update_dart_sdk.sh
+++ b/bin/internal/update_dart_sdk.sh
@@ -39,6 +39,23 @@ if [ ! -f "$ENGINE_STAMP" ] || [ "$ENGINE_VERSION" != `cat "$ENGINE_STAMP"` ]; t
     echo
     exit 1
   }
+  command -v unzip > /dev/null 2>&1 || {
+    echo
+    echo 'Missing "unzip" tool. Unable to extract Dart SDK.'
+    case "$(uname -s)" in
+      Darwin)
+        echo 'Consider running "brew install unzip".'
+        ;;
+      Linux)
+        echo 'Consider running "sudo apt-get install unzip".'
+        ;;
+      *)
+        echo "Please install unzip."
+        ;;
+    esac
+    echo
+    exit 1
+  }
   echo "Downloading Dart SDK from Flutter engine $ENGINE_VERSION..."
 
   case "$(uname -s)" in