diff --git a/Cargo.toml b/Cargo.toml
index 007c7839..e5cb743d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -89,7 +89,9 @@ which = "4.2.5"
 
 [dev-dependencies]
 align-data = "0.1.0"
+fslock = "0.1.8"
 trybuild = "1.0.61"
+which = "4.2.5"
 
 [[example]]
 name = "hello_world"
@@ -100,5 +102,9 @@ name = "shell"
 [[example]]
 name = "process"
 
+[[test]]
+name = "buid"
+path = "build.rs"
+
 [workspace]
 members = ["examples/android"]
diff --git a/build.rs b/build.rs
index e57bb0de..cf6ff07a 100644
--- a/build.rs
+++ b/build.rs
@@ -832,6 +832,7 @@ pub fn parse_ninja_graph(s: &str) -> HashSet<String> {
 #[cfg(test)]
 mod test {
   use super::*;
+
   const MOCK_GRAPH: &str = r#"
 digraph ninja {
 rankdir="LR"