diff --git a/.envrc b/.envrc
index 38764da7a..e6505ace6 100644
--- a/.envrc
+++ b/.envrc
@@ -1,3 +1,9 @@
 # shellcheck shell=bash
 source_env_if_exists .envrc.local
+# TODO: `use flake .#native-clangStdenvPackages` on macOS?
 use flake ".#${LIX_SHELL_VARIANT:-default}" "${LIX_SHELL_EXTRA_ARGS[@]}"
+export MAKEFLAGS="$MAKEFLAGS -e"
+if [[ -n "$NIX_BUILD_CORES" ]]; then
+    export MAKEFLAGS="$MAKEFLAGS -j $NIX_BUILD_CORES"
+fi
+export GTEST_BRIEF=1
diff --git a/.gitignore b/.gitignore
index 4527ab45f..d08d04ccf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -157,3 +157,5 @@ result-*
 
 # ClangBuildAnalyzer output, see maintainers/buildtime_report.sh
 buildtime.bin
+
+.envrc.local