diff --git a/install.py b/install.py
index b36ba9e..925eb39 100755
--- a/install.py
+++ b/install.py
@@ -89,9 +89,12 @@ class Installer:
         if executable:
             p_dest.chmod(0o755)
 
-    def do_run(self, command: str) -> None:
+    def do_run(self, *, command: str, condition: str = 'true') -> None:
         """Run a command."""
 
+        if not evaluate_condition(condition):
+            return
+
         ui.info_2("Running", "`{}`".format(command))
         subprocess.run(command, check=True, shell=True)
         self.base_dir.chdir()
@@ -210,7 +213,7 @@ class Installer:
 def evaluate_condition(command: str) -> bool:
     """Run a bash command. On success return True, else return False."""
 
-    return subprocess.run(command, shell=True).returncode == 0
+    return subprocess.run(command, check=False, shell=True).returncode == 0
 
 
 def main() -> None: