diff --git a/README.md b/README.md
index ad4fab1..325511f 100644
--- a/README.md
+++ b/README.md
@@ -77,6 +77,21 @@ looks good to me!
 
 as it'll try to build `list` `of` `attrs` `looks` `good` `to` `me!`.
 
+
+# Why did my build fail?
+
+
+Builds are run like:
+
+> HOME=/homeless-shelter NIX_PATH=nixpkgs=$(pwd) nix-build ./default.nix \
+> --no-out-link --keep-going -A hello \
+> --option restrict-eval true \
+> --option build-timeout 1800 \
+> --argstr system thesystem
+
+
+---
+
 # arch
 
 1. All github events go in to web/index.php, which sends the event to
diff --git a/factoids.toml b/factoids.toml
index 35a9feb..c75b8e1 100644
--- a/factoids.toml
+++ b/factoids.toml
@@ -2,6 +2,7 @@
 "!factoids" = "Have a helpful Nix factoid? Send a PR! https://github.com/grahamc/ofborg/blob/released/factoids.toml"
 "!cloudfront" = "https://gist.github.com/grahamc/df1bb806eb3552650d03eef7036a72ba"
 "!which channel" = "https://gist.github.com/grahamc/c60578c6e6928043d29a427361634df6#which-channel-is-right-for-me"
+"!pills" = "https://nixos.org/nixos/nix-pills"
 "!stuck" = "https://howoldis.herokuapp.com/"
 "!doesanyoneuse" = "Don't ask if anyone uses software xyz, just ask your specific question. This helps solve your problem quicker, and allows people who haven't used xyz but may still be able to help you to do so."
 "!library" = "Don't install libraries through nix-env or systemPackages. See https://nixos.wiki/wiki/FAQ#I_installed_a_library_but_my_compiler_is_not_finding_it._Why.3F for details."