1 files changed, 24 insertions, 0 deletions
diff --git a/pkgs/build-support/node/fetch-yarn-deps/yarn-build-hook.sh b/pkgs/build-support/node/fetch-yarn-deps/yarn-build-hook.sh
new file mode 100644
index 0000000000000..947aa1736b6f7
--- /dev/null
+++ b/pkgs/build-support/node/fetch-yarn-deps/yarn-build-hook.sh
@@ -0,0 +1,24 @@
+yarnBuildHook() {
+    runHook preBuild
+    echo "Executing yarnBuildHook"
+
+    if [ -z "${yarnBuildScript-}" ]; then
+        yarnBuildScript="build"
+    fi
+
+    if ! type node > /dev/null 2>&1 ; then
+        echo yarnConfigHook WARNING: a node interpreter was not added to the \
+            build, and is probably required to run \'yarn $yarnBuildHook\'. \
+            A common symptom of this is getting \'command not found\' errors \
+            for Nodejs related tools.
+    fi
+
+    yarn --offline "$yarnBuildScript" $yarnBuildFlags
+
+    echo "finished yarnBuildHook"
+    runHook postBuild
+}
+
+if [[ -z "${dontYarnBuild-}" && -z "${buildPhase-}" ]]; then
+    buildPhase=yarnBuildHook
+fi