Fix race condition in build (#477)

* Fix race condition in build

* Add changeset

3 files changed, 10 insertions, 5 deletions

diff --git a/.changeset/slow-apricots-doubt.md b/.changeset/slow-apricots-doubt.md
new file mode 100644
index 000000000..c5bd8ebeb
--- /dev/null
+++ b/.changeset/slow-apricots-doubt.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fix race condition caused by parallel build
diff --git a/packages/astro/package.json b/packages/astro/package.json
index 0a736072c..8e482da06 100644
--- a/packages/astro/package.json
+++ b/packages/astro/package.json
@@ -92,7 +92,7 @@
     "sass": "^1.32.13",
     "shorthash": "^0.0.2",
     "slash": "^4.0.0",
-    "snowpack": "^3.5.8",
+    "snowpack": "^3.5.9",
     "source-map-support": "^0.5.19",
     "string-width": "^5.0.0",
     "tiny-glob": "^0.2.8",
diff --git a/yarn.lock b/yarn.lock
index ecffdac59..5be83d7fa 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -8935,10 +8935,10 @@ smartwrap@^1.2.3:
     wcwidth "^1.0.1"
     yargs "^15.1.0"
 
-snowpack@^3.5.8:
-  version "3.5.8"
-  resolved "https://registry.yarnpkg.com/snowpack/-/snowpack-3.5.8.tgz#2132cca27e593aee619df671dcc68290c0b68889"
-  integrity sha512-o0oyNpjnmFywPPgNhVt8ofa2RPBQqScxnFNbf15H9B+sH5UyrgYmy4qeJAnipsQqT9CT7i9Mx2Q5Ccm5vlfHSQ==
+snowpack@^3.5.9:
+  version "3.5.9"
+  resolved "https://registry.yarnpkg.com/snowpack/-/snowpack-3.5.9.tgz#c374c6b8633ec5baf8311adc964238edeea67b3b"
+  integrity sha512-Rajenx5DRDiMKC+GiU1vMP+tcjge9bAe35fGsPdhkTtIwRkV3u4he1TfiwTh8F1hcOcG5IzLe8jqGM9sBANtpw==
   dependencies:
     cli-spinners "^2.5.0"
     default-browser-id "^2.0.0"