lib.mkDevShell: handle custom shell and empty tools or env

1 files changed, 2 insertions, 0 deletions

diff --git a/readme.md b/readme.md
index 88c4d4a..e4ba8dd 100644
--- a/readme.md
+++ b/readme.md
@@ -48,6 +48,8 @@ Functions documentation provided as comments below.
         PGDATABASE = "app";
         DATABASE_URL = "postgresql:///${PGDATABASE}?host=${PGHOST}";
       };
+
+      shell = null;
     };
 
   });