diff --git a/backend/test-runner.js b/backend/test-runner.js
index 4564674..6a054b2 100644
--- a/backend/test-runner.js
+++ b/backend/test-runner.js
@@ -165,15 +165,21 @@ class Test {
       this.handleUpdate = () => {
         if (this.timedOut) {
           reject(new Error(`timeout while waiting for ${desc}`));
-        } else {
-          while (this.handledMessages < this.messages.length) {
-            const msg = this.messages[this.handledMessages];
-            const result = handler(msg);
-            if (![undefined, null, false].includes(result)) {
-              resolve(result);
-            }
-            this.handledMessages += 1;
+          return;
+        }
+        while (this.handledMessages < this.messages.length) {
+          const msg = this.messages[this.handledMessages];
+          let result;
+          try {
+            result = handler(msg);
+          } catch (err) {
+            reject(err);
+            return;
           }
+          if (![undefined, null, false].includes(result)) {
+            resolve(result);
+          }
+          this.handledMessages += 1;
         }
       };
       this.handleUpdate();
@@ -222,8 +228,8 @@ class Test {
     await this.waitForOutput(pattern, this.config.helloMaxLength);
     if (!this.config.repl) {
       await this.wait("termination", (msg) => {
-        if (msg.event === "serviceFailed") {
-          if (msg.code !== 0) {
+        if (msg.event === "serviceFailed" && msg.service === "terminal") {
+          if (msg.code !== (this.config.helloStatus || 0)) {
             throw new Error(`run failed with code ${msg.code}`);
           }
           return true;
diff --git a/langs/dylan.yaml b/langs/dylan.yaml
index 858fed7..9525d87 100644
--- a/langs/dylan.yaml
+++ b/langs/dylan.yaml
@@ -53,6 +53,6 @@ template: |
   main(application-name(), application-arguments());
 
 compile: |
-  dylan-compiler -build main.lid
+  dylan-compiler -build main.lid && echo
 run: |
   _build/bin/main
diff --git a/langs/ec.yaml b/langs/ec.yaml
index bf3850e..73a26a8 100644
--- a/langs/ec.yaml
+++ b/langs/ec.yaml
@@ -58,3 +58,4 @@ compile: |
   clang main.c main.main.c -lecereCOM -o main
 run: |
   ./main
+helloStatus: 139
diff --git a/langs/limbo.yaml b/langs/limbo.yaml
index 34bae52..0e1b2d7 100644
--- a/langs/limbo.yaml
+++ b/langs/limbo.yaml
@@ -64,3 +64,4 @@ compile: |
   limbo -o riju/main.dis riju/main.b
 run: |
   emu -r . riju/main.dis
+helloStatus: 137
diff --git a/lib/jsonschema.yaml b/lib/jsonschema.yaml
index 168357d..a8bf7ee 100644
--- a/lib/jsonschema.yaml
+++ b/lib/jsonschema.yaml
@@ -844,6 +844,19 @@ properties:
       the regular expression.)
     type: integer
     minimum: 1
+  helloStatus:
+    title: "Expected exit status for 'run' test"
+    description: |
+      By default, the 'run' command is expected to exit with status 0
+      when run on the 'template' code (after printing "Hello,
+      world!"). In the case that the exit status is something else, it
+      can be overridden.
+
+      This only has an effect if 'repl' is *not* specified.
+    type: integer
+    minimum: 0
+    maximum: 255
+    default: 0
   runReplInput:
     title: "REPL input for 'runrepl' test specifically"
     description: |
diff --git a/supervisor/src/main.go b/supervisor/src/main.go
index ad6d96a..3fac4ed 100644
--- a/supervisor/src/main.go
+++ b/supervisor/src/main.go
@@ -388,7 +388,7 @@ func (sv *supervisor) reload() error {
 	return nil
 }
 
-var rijuContainerRegexp = regexp.MustCompile(`^([^|]+):([^|]+)\|([^|]+)$`)
+var rijuContainerRegexp = regexp.MustCompile(`^([^|]+)\|([^|]+)\|([^|]+)$`)
 
 func main() {
 	supervisorCfg := supervisorConfig{}
diff --git a/system/res/docker-exec.py b/system/res/docker-exec.py
index 8d13799..b442645 100755
--- a/system/res/docker-exec.py
+++ b/system/res/docker-exec.py
@@ -64,7 +64,7 @@ runuser_args = []
 if args.user:
     runuser_args = ["runuser", "-u", args.user, "--"]
 
-subprocess.run([
+sys.exit(subprocess.run([
     "docker",
     "exec",
     *exec_args,
@@ -81,4 +81,4 @@ exec "$@"
     "--",
     *runuser_args,
     *args.arg,
-])
+]).returncode)