From 8519480fe45be6861a52e87d1708c79437aa517a Mon Sep 17 00:00:00 2001
From: Magnus Hoff <maghoff@gmail.com>
Date: Mon, 20 Nov 2017 10:26:35 +0100
Subject: [PATCH] Use build.rs to properly trigger rebuilds when env vars
 change, for #44

---
 build.rs            | 9 +++++++++
 src/build_config.rs | 3 +++
 2 files changed, 12 insertions(+)

diff --git a/build.rs b/build.rs
index 2e1ad6c..9e1a2b7 100644
--- a/build.rs
+++ b/build.rs
@@ -45,4 +45,13 @@ fn main() {
     for entry in WalkDir::new("migrations").into_iter().filter_map(|e| e.ok()) {
         println!("cargo:rerun-if-changed={}", entry.path().display());
     }
+
+    // For build_config.rs
+    for env_var in &[
+        "CONTINUOUS_INTEGRATION",
+        "TRAVIS_BRANCH",
+        "TRAVIS_COMMIT",
+    ] {
+        println!("cargo:rerun-if-env-changed={}", env_var);
+    }
 }
diff --git a/src/build_config.rs b/src/build_config.rs
index dd0f9ac..afdf9dc 100644
--- a/src/build_config.rs
+++ b/src/build_config.rs
@@ -1,5 +1,8 @@
 #![allow(dead_code)]
 
+// The non-CARGO env variables used here must be listed
+// in build.rs to properly trigger rebuild on change
+
 pub const PROJECT_NAME: &str = env!("CARGO_PKG_NAME");
 
 lazy_static! {