{ stdenv }: # helper functions for packaging programs with plugin systems { /* Takes a list of expected plugin names * and compares it to the found plugins given in the file, * one plugin per line. * If the lists differ, the build fails with a nice message. * * This is helpful to ensure maintainers don’t miss * the addition or removal of a plugin. */ diffPlugins = expectedPlugins: foundPluginsFilePath: '' # sort both lists first plugins_expected=$(mktemp) (${stdenv.lib.concatMapStrings (s: "echo \"${s}\";") expectedPlugins}) \ | sort -u > "$plugins_expected" plugins_found=$(mktemp) sort -u "${foundPluginsFilePath}" > "$plugins_found" if ! mismatches="$(diff -y "$plugins_expected" "$plugins_found")"; then echo "The the list of expected plugins (left side) doesn't match" \ "the list of plugins we found (right side):" >&2 echo "$mismatches" >&2 exit 1 fi ''; }