diff --git a/ofborg/src/nix.rs b/ofborg/src/nix.rs
index e0bb21a..df0bada 100644
--- a/ofborg/src/nix.rs
+++ b/ofborg/src/nix.rs
@@ -1,8 +1,7 @@
 use crate::asynccmd::{AsyncCmd, SpawnedAsyncCmd};
+use crate::message::buildresult::BuildStatus;
 use crate::ofborg::partition_result;
 
-use tempfile::tempfile;
-
 use std::collections::HashMap;
 use std::env;
 use std::ffi::OsStr;
@@ -12,6 +11,8 @@ use std::io::{BufRead, BufReader, Seek, SeekFrom};
 use std::path::Path;
 use std::process::{Command, Stdio};
 
+use tempfile::tempfile;
+
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub enum File {
     DefaultNixpkgs,
@@ -358,6 +359,25 @@ pub fn is_user_setting_warning(line: &str) -> bool {
         && line.ends_with("because it is a restricted setting and you are not a trusted user")
 }
 
+pub fn wait_for_build_status(spawned: SpawnedAsyncCmd) -> BuildStatus {
+    match spawned.wait() {
+        Ok(s) => match s.code() {
+            Some(0) => BuildStatus::Success,
+            Some(100) => BuildStatus::Failure, // nix permanent failure
+            Some(101) => BuildStatus::TimedOut, // nix build timedout
+            Some(i) => BuildStatus::UnexpectedError {
+                err: format!("command failed with exit code {}", i),
+            },
+            None => BuildStatus::UnexpectedError {
+                err: "unexpected build failure".into(),
+            },
+        },
+        e => BuildStatus::UnexpectedError {
+            err: format!("failed on interior command {:?}", e),
+        },
+    }
+}
+
 #[cfg(test)]
 mod tests {
     fn nix() -> Nix {
diff --git a/ofborg/src/tasks/build.rs b/ofborg/src/tasks/build.rs
index 4f0721c..cce1925 100644
--- a/ofborg/src/tasks/build.rs
+++ b/ofborg/src/tasks/build.rs
@@ -361,23 +361,7 @@ impl notifyworker::SimpleNotifyWorker for BuildWorker {
             actions.log_line(&line);
         }
 
-        // TODO: this belongs in the nix module.
-        let status = match spawned.wait() {
-            Ok(s) => match s.code() {
-                Some(0) => BuildStatus::Success,
-                Some(100) => BuildStatus::Failure, // nix permanent failure
-                Some(101) => BuildStatus::TimedOut, // nix build timedout
-                Some(i) => BuildStatus::UnexpectedError {
-                    err: format!("command failed with exit code {}", i),
-                },
-                None => BuildStatus::UnexpectedError {
-                    err: "unexpected build failure".into(),
-                },
-            },
-            e => BuildStatus::UnexpectedError {
-                err: format!("failed on interior command {:?}", e),
-            },
-        };
+        let status = nix::wait_for_build_status(spawned);
 
         info!("ok built ({:?}), building", status);
         info!("Lines:");