whatsupnix: init

Import from https://github.com/NixOS/nix/issues/443#issuecomment-296752535

krebs/5pkgs/whatsupnix/default.nix

@@ -0,0 +1,15 @@
+{ bash, coreutils, gawk, nix, makeWrapper, stdenv }:
+
+stdenv.mkDerivation {
+  name = "whatsupnix";
+  phases = [ "installPhase" ];
+  nativeBuildInputs = [ makeWrapper ];
+  installPhase = ''
+    mkdir -p $out/bin
+    cat - ${./whatsupnix.bash} > $out/bin/whatsupnix <<\EOF
+    #! ${bash}/bin/bash
+    export PATH=${stdenv.lib.makeBinPath [ coreutils gawk nix ]}
+    EOF
+    chmod +x $out/bin/whatsupnix
+  '';
+}

krebs/5pkgs/whatsupnix/whatsupnix.bash

@@ -0,0 +1,44 @@
+#!/usr/bin/env bash
+
+# Prints build logs for failed derivations in quiet build mode (-Q).
+# See https://github.com/NixOS/nix/issues/443
+#
+# Usage:
+#
+#    set -o pipefail
+#    nix-build ... -Q ... | whatsupnix
+#
+
+
+GAWK=${GAWK:-gawk}
+NIX_STORE=${NIX_STORE:-nix-store}
+
+broken=$(mktemp)
+trap 'rm -f -- "$broken"' EXIT
+
+exec >&2
+
+$GAWK -v broken="$broken" -f <(cat - <<- 'AWK'
+  match($0, /builder for .*(\/nix\/store\/.+\.drv).* failed/, m) {
+    print m[1] >> broken
+  }
+  { print $0 }
+AWK
+)
+
+export NIX_PAGER='' # for nix-store
+while read -r drv; do
+  title="** FAILED $drv LOG  **"
+  frame=${title//?/*}
+
+  echo "$frame"
+  echo "$title"
+  echo "$frame"
+  echo
+
+  $NIX_STORE -l "$drv"
+
+  echo
+done < "$broken"
+
+exit 0