comment once on a merged config pr when its swarm build fails

swarm-controller/src/config_pr.rs

@@ -73,11 +73,13 @@ struct WebhookBranch {
     sha: Option<String>,
 }
 
-/// A config PR that was just merged: whose config, and the commit to deploy.
+/// A config PR that was just merged: whose config, the commit to deploy, and
+/// the PR.
 #[derive(Debug, PartialEq, Eq)]
 pub struct MergedConfigPr {
     pub agent: String,
     pub rev: String,
+    pub pr: u64,
 }
 
 /// The merge a verified `ConfigPr` delivery reports, if it reports one.
@@ -108,6 +110,7 @@ pub fn merged(body: &[u8]) -> Option<MergedConfigPr> {
     Some(MergedConfigPr {
         agent: payload.repository.name,
         rev,
+        pr: payload.pull_request.number,
     })
 }
 
@@ -373,6 +376,7 @@ mod tests {
             Some(super::MergedConfigPr {
                 agent: "damocles".to_owned(),
                 rev: "abc123".to_owned(),
+                pr: 5,
             })
         );
     }